From 74ecd395081dfc527c3c6be4bad85194ad0c1c65 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 26 Jun 2020 14:54:43 +0200
Subject: [PATCH 01/97] LEN function

---
 src/i18n/languages/csCZ.ts            |  1 +
 src/i18n/languages/daDK.ts            |  1 +
 src/i18n/languages/deDE.ts            |  1 +
 src/i18n/languages/enGB.ts            |  1 +
 src/i18n/languages/esES.ts            |  1 +
 src/i18n/languages/fiFI.ts            |  1 +
 src/i18n/languages/frFR.ts            |  1 +
 src/i18n/languages/huHU.ts            |  1 +
 src/i18n/languages/itIT.ts            |  1 +
 src/i18n/languages/nbNO.ts            |  1 +
 src/i18n/languages/nlNL.ts            |  1 +
 src/i18n/languages/plPL.ts            |  1 +
 src/i18n/languages/ptPT.ts            |  1 +
 src/i18n/languages/ruRU.ts            |  1 +
 src/i18n/languages/svSE.ts            |  1 +
 src/i18n/languages/trTR.ts            |  1 +
 src/interpreter/plugin/TextPlugin.ts  |  9 +++++++
 test/interpreter/function-len.spec.ts | 34 +++++++++++++++++++++++++++
 18 files changed, 59 insertions(+)
 create mode 100644 test/interpreter/function-len.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index cde62afc16..1539f49ad3 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'JE.ČISLO',
     ISODD: 'ISODD',
     ISTEXT: 'JE.TEXT',
+    LEN: 'DÉLKA',
     LN: 'LN',
     LOG: 'LOGZ',
     LOG10: 'LOG',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 588c11e082..940b33b55b 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ER.TAL',
     ISODD: 'ER.ULIGE',
     ISTEXT: 'ER.TEKST',
+    LEN: 'LÆNGDE',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 6fba432733..bbe2a02033 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ISTZAHL',
     ISODD: 'ISTUNGERADE',
     ISTEXT: 'ISTTEXT',
+    LEN: 'LÄNGE',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 6d5c7f51b0..0837ae90c2 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ISNUMBER',
     ISODD: 'ISODD',
     ISTEXT: 'ISTEXT',
+    LEN: 'LEN',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 5ade8c54e5..999cb051a3 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -80,6 +80,7 @@ export const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ESNUMERO',
     ISODD: 'ES.IMPAR',
     ISTEXT: 'ESTEXTO',
+    LEN: 'LARGO',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index c46d11d424..d36048078e 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ONLUKU',
     ISODD: 'ONPARITON',
     ISTEXT: 'ONTEKSTI',
+    LEN: 'PITUUS',
     LN: 'LUONNLOG',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 7befe0f217..6591373775 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ESTNUM',
     ISODD: 'EST.IMPAIR',
     ISTEXT: 'ESTTEXTE',
+    LEN: 'NBCAR',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 0f72282b01..bdad0c7736 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'SZÁM',
     ISODD: 'PÁRATLANE',
     ISTEXT: 'SZÖVEG.E',
+    LEN: 'HOSSZ',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 166b82e7bc..67ad42ad44 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'VAL.NUMERO',
     ISODD: 'VAL.DISPARI',
     ISTEXT: 'VAL.TESTO',
+    LEN: 'LUNGHEZZA',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 0294e4f404..ae807d8e15 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ERTALL',
     ISODD: 'ERODDE',
     ISTEXT: 'ERTEKST',
+    LEN: 'LENGDE',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index 7de90f72a4..b9b774da69 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ISGETAL',
     ISODD: 'IS.ONEVEN',
     ISTEXT: 'ISTEKST',
+    LEN: 'PITUUS',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index 96bb78e8af..f7f6426ed2 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'CZY.LICZBA',
     ISODD: 'CZY.NIEPARZYSTE',
     ISTEXT: 'CZY.TEKST',
+    LEN: 'DŁ',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index c6a484678d..d96baea476 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ÉNÚM',
     ISODD: 'ÉIMPAR',
     ISTEXT: 'ÉTEXTO',
+    LEN: 'NÚM.CARACT',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 8b1d05c5df..ea0edf0202 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ЕЧИСЛО',
     ISODD: 'ЕНЕЧЁТ',
     ISTEXT: 'ЕТЕКСТ',
+    LEN: 'ДЛСТР',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 0cdca3717e..d27f2ffaed 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ÄRTAL',
     ISODD: 'ÄRUDDA',
     ISTEXT: 'ÄRTEXT',
+    LEN: 'LÄNGD',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 439fe14ec3..e88bc447a7 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -80,6 +80,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ESAYIYSA',
     ISODD: 'TEKMİ',
     ISTEXT: 'EMETİNSE',
+    LEN: 'UZUNLUK',
     LN: 'LN',
     LOG: 'LOG',
     LOG10: 'LOG10',
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 475c5afb1f..0985125116 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -19,6 +19,9 @@ export class TextPlugin extends FunctionPlugin {
     'SPLIT': {
       method: 'split',
     },
+    'LEN': {
+      method: 'len'
+    }
   }
 
   /**
@@ -84,4 +87,10 @@ export class TextPlugin extends FunctionPlugin {
 
     return splittedString[indexToUse]
   }
+
+  public len(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
+      return arg.length
+    })
+  }
 }
diff --git a/test/interpreter/function-len.spec.ts b/test/interpreter/function-len.spec.ts
new file mode 100644
index 0000000000..f15b408163
--- /dev/null
+++ b/test/interpreter/function-len.spec.ts
@@ -0,0 +1,34 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function LEN', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEN()'],
+      ['=LEN("foo", "bar")']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should work', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEN("foo")']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(3)
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEN(1)'],
+      ['=LEN(5+5)'],
+      ['=LEN(TRUE())'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A2'))).toEqual(2)
+    expect(engine.getCellValue(adr('A3'))).toEqual(4)
+  })
+})
\ No newline at end of file

From d202b51e3ca58e7e92f792879eb00d8fa9020aa6 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 26 Jun 2020 15:40:05 +0200
Subject: [PATCH 02/97] TRIM function

---
 src/i18n/languages/csCZ.ts             |  1 +
 src/i18n/languages/daDK.ts             |  1 +
 src/i18n/languages/deDE.ts             |  1 +
 src/i18n/languages/enGB.ts             |  1 +
 src/i18n/languages/esES.ts             |  1 +
 src/i18n/languages/fiFI.ts             |  1 +
 src/i18n/languages/frFR.ts             |  1 +
 src/i18n/languages/huHU.ts             |  1 +
 src/i18n/languages/itIT.ts             |  1 +
 src/i18n/languages/nbNO.ts             |  1 +
 src/i18n/languages/nlNL.ts             |  1 +
 src/i18n/languages/plPL.ts             |  1 +
 src/i18n/languages/ptPT.ts             |  1 +
 src/i18n/languages/ruRU.ts             |  1 +
 src/i18n/languages/svSE.ts             |  1 +
 src/i18n/languages/trTR.ts             |  1 +
 src/interpreter/plugin/TextPlugin.ts   |  9 ++++++
 test/interpreter/function-trim.spec.ts | 40 ++++++++++++++++++++++++++
 18 files changed, 65 insertions(+)
 create mode 100644 test/interpreter/function-trim.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 1539f49ad3..39dae1dafe 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TG',
     TEXT: 'HODNOTA.NA.TEXT',
     TRANSPOSE: 'TRANSPOZICE',
+    TRIM: 'PROČISTIT',
     TRUE: 'PRAVDA',
     TRUNC: 'USEKNOUT',
     VLOOKUP: 'SVYHLEDAT',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 940b33b55b..ad9f6125bd 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEKST',
     TRANSPOSE: 'TRANSPONER',
+    TRIM: 'FJERN.OVERFLØDIGE.BLANKE',
     TRUE: 'TRUE',
     TRUNC: 'AFKORT',
     VLOOKUP: 'LOPSLAG',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index bbe2a02033..a636670d93 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEXT',
     TRANSPOSE: 'MTRANS',
+    TRIM: 'GLÄTTEN',
     TRUE: 'WAHR',
     TRUNC: 'KÜRZEN',
     VLOOKUP: 'SVERWEIS',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 0837ae90c2..9a1c03038a 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEXT',
     TRANSPOSE: 'TRANSPOSE',
+    TRIM: 'TRIM',
     TRUE: 'TRUE',
     TRUNC: 'TRUNC',
     VLOOKUP: 'VLOOKUP',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 999cb051a3..6ef0c55e28 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -119,6 +119,7 @@ export const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEXTO',
     TRANSPOSE: 'TRANSPONER',
+    TRIM: 'ESPACIOS',
     TRUE: 'VERDADERO',
     TRUNC: 'TRUNCAR',
     VLOOKUP: 'BUSCARV',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index d36048078e..678e739a9c 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEKSTI',
     TRANSPOSE: 'TRANSPONOI',
+    TRIM: 'POISTA.VÄLIT',
     TRUE: 'TOSI',
     TRUNC: 'KATKAISE',
     VLOOKUP: 'PHAKU',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 6591373775..1901c03b0b 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEXTE',
     TRANSPOSE: 'TRANSPOSE',
+    TRIM: 'SUPPRESPACE',
     TRUE: 'VRAI',
     TRUNC: 'TRONQUE',
     VLOOKUP: 'RECHERCHEV',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index bdad0c7736..99b75c7706 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'SZÖVEG',
     TRANSPOSE: 'TRANSZPONÁLÁS',
+    TRIM: 'KIMETSZ',
     TRUE: 'IGAZ',
     TRUNC: 'CSONK',
     VLOOKUP: 'FKERES',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 67ad42ad44..8b7f37d3a3 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TESTO',
     TRANSPOSE: 'MATR.TRASPOSTA',
+    TRIM: 'ANNULLA.SPAZI',
     TRUE: 'VERO',
     TRUNC: 'TRONCA',
     VLOOKUP: 'CERCA.VERT',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index ae807d8e15..ae104a2efc 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEKST',
     TRANSPOSE: 'TRANSPONER',
+    TRIM: 'TRIMME',
     TRUE: 'SANN',
     TRUNC: 'AVKORT',
     VLOOKUP: 'FINN.RAD',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index b9b774da69..fa2415880e 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEKST',
     TRANSPOSE: 'TRANSPONEREN',
+    TRIM: 'SPATIES.WISSEN',
     TRUE: 'WAAR',
     TRUNC: 'GEHEEL',
     VLOOKUP: 'VERT.ZOEKEN',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index f7f6426ed2..bcd18afcd4 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEKST',
     TRANSPOSE: 'TRANSPONUJ',
+    TRIM: 'USUŃ.ZBĘDNE.ODSTĘPY',
     TRUE: 'PRAWDA',
     TRUNC: 'LICZBA.CAŁK',
     VLOOKUP: 'WYSZUKAJ.PIONOWO',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index d96baea476..ef8540ef26 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEXTO',
     TRANSPOSE: 'TRANSPOR',
+    TRIM: 'ARRUMAR',
     TRUE: 'VERDADEIRO',
     TRUNC: 'TRUNCAR',
     VLOOKUP: 'PROCV',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index ea0edf0202..b302d70876 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'ТЕКСТ',
     TRANSPOSE: 'ТРАНСП',
+    TRIM: 'СЖПРОБЕЛЫ',
     TRUE: 'ИСТИНА',
     TRUNC: 'ОТБР',
     VLOOKUP: 'ВПР',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index d27f2ffaed..1a3d4068d4 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'TEXT',
     TRANSPOSE: 'TRANSPONERA',
+    TRIM: 'RENSA',
     TRUE: 'SANT',
     TRUNC: 'AVKORTA',
     VLOOKUP: 'LETARAD',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index e88bc447a7..b65d012e51 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -119,6 +119,7 @@ const dictionary: RawTranslationPackage = {
     TAN: 'TAN',
     TEXT: 'METNEÇEVİR',
     TRANSPOSE: 'DEVRİK_DÖNÜŞÜM',
+    TRIM: 'KIRP',
     TRUE: 'DOĞRU',
     TRUNC: 'NSAT',
     VLOOKUP: 'DÜŞEYARA',
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 0985125116..4fb0a97e62 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -21,6 +21,9 @@ export class TextPlugin extends FunctionPlugin {
     },
     'LEN': {
       method: 'len'
+    },
+    'TRIM': {
+      method: 'trim'
     }
   }
 
@@ -93,4 +96,10 @@ export class TextPlugin extends FunctionPlugin {
       return arg.length
     })
   }
+
+  public trim(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
+      return arg.replace(/^ +| +$/g, '').replace(/ +/g, ' ')
+    })
+  }
 }
diff --git a/test/interpreter/function-trim.spec.ts b/test/interpreter/function-trim.spec.ts
new file mode 100644
index 0000000000..520beb9a41
--- /dev/null
+++ b/test/interpreter/function-trim.spec.ts
@@ -0,0 +1,40 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function TRIM', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=TRIM()'],
+      ['=TRIM("foo", "bar")']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should work', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=TRIM("   foo")'],
+      ['=TRIM("foo   ")'],
+      ['=TRIM(" foo   ")'],
+      ['=TRIM(" f    o  o   ")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('foo')
+    expect(engine.getCellValue(adr('A2'))).toEqual('foo')
+    expect(engine.getCellValue(adr('A3'))).toEqual('foo')
+    expect(engine.getCellValue(adr('A4'))).toEqual('f o o')
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=TRIM(1)'],
+      ['=TRIM(5+5)'],
+      ['=TRIM(TRUE())'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('1')
+    expect(engine.getCellValue(adr('A2'))).toEqual('10')
+    expect(engine.getCellValue(adr('A3'))).toEqual('TRUE')
+  })
+})
\ No newline at end of file

From 04b2938bcca69225c331291f8030d627c1541c08 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 26 Jun 2020 15:58:06 +0200
Subject: [PATCH 03/97] PROPER function

---
 src/i18n/languages/csCZ.ts               |  1 +
 src/i18n/languages/daDK.ts               |  1 +
 src/i18n/languages/deDE.ts               |  1 +
 src/i18n/languages/enGB.ts               |  1 +
 src/i18n/languages/esES.ts               |  1 +
 src/i18n/languages/fiFI.ts               |  1 +
 src/i18n/languages/frFR.ts               |  1 +
 src/i18n/languages/huHU.ts               |  1 +
 src/i18n/languages/itIT.ts               |  1 +
 src/i18n/languages/nbNO.ts               |  1 +
 src/i18n/languages/nlNL.ts               |  1 +
 src/i18n/languages/plPL.ts               |  1 +
 src/i18n/languages/ptPT.ts               |  1 +
 src/i18n/languages/ruRU.ts               |  1 +
 src/i18n/languages/svSE.ts               |  1 +
 src/i18n/languages/trTR.ts               |  1 +
 src/interpreter/plugin/TextPlugin.ts     |  9 ++++++
 test/interpreter/function-proper.spec.ts | 40 ++++++++++++++++++++++++
 18 files changed, 65 insertions(+)
 create mode 100644 test/interpreter/function-proper.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 39dae1dafe..b538ad0f96 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'NEBO',
     PI: 'PI',
     POWER: 'POWER',
+    PROPER: 'VELKÁ2',
     RADIANS: 'RADIANS',
     RAND: 'NÁHČÍSLO',
     ROUND: 'ZAOKROUHLIT',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index ad9f6125bd..3d1dd7acfa 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'ELLER',
     PI: 'PI',
     POWER: 'POTENS',
+    PROPER: 'STORT.FORBOGSTAV',
     RADIANS: 'RADIANER',
     RAND: 'SLUMP',
     ROUND: 'AFRUND',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index a636670d93..87d7532ac0 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'ODER',
     PI: 'PI',
     POWER: 'POTENZ',
+    PROPER: 'GROSS2',
     RADIANS: 'BOGENMASS',
     RAND: 'ZUFALLSZAHL',
     ROUND: 'RUNDEN',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 9a1c03038a..f1356aae78 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'OR',
     PI: 'PI',
     POWER: 'POWER',
+    PROPER: 'PROPER',
     RADIANS: 'RADIANS',
     RAND: 'RAND',
     ROUND: 'ROUND',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 6ef0c55e28..8d34609374 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -101,6 +101,7 @@ export const dictionary: RawTranslationPackage = {
     OR: 'O',
     PI: 'PI',
     POWER: 'POTENCIA',
+    PROPER: 'NOMPROPIO',
     RADIANS: 'RADIANES',
     RAND: 'ALEATORIO',
     ROUND: 'REDONDEAR',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 678e739a9c..fdf70fc27f 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'TAI',
     PI: 'PII',
     POWER: 'POTENSSI',
+    PROPER: 'ERISNIMI',
     RADIANS: 'RADIAANIT',
     RAND: 'SATUNNAISLUKU',
     ROUND: 'PYÖRISTÄ',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 1901c03b0b..5a86324768 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'OU',
     PI: 'PI',
     POWER: 'PUISSANCE',
+    PROPER: 'NOMPROPRE',
     RADIANS: 'RADIANS',
     RAND: 'ALEA',
     ROUND: 'ARRONDI',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 99b75c7706..af29147d87 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'VAGY',
     PI: 'PI',
     POWER: 'HATVÁNY',
+    PROPER: 'TNÉV',
     RADIANS: 'RADIÁN',
     RAND: 'VÉL',
     ROUND: 'KEREKÍTÉS',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 8b7f37d3a3..d0d693746e 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'O',
     PI: 'PI.GRECO',
     POWER: 'POTENZA',
+    PROPER: 'MAIUSC.INIZ',
     RADIANS: 'RADIANTI',
     RAND: 'CASUALE',
     ROUND: 'ARROTONDA',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index ae104a2efc..0c877ea383 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'ELLER',
     PI: 'PI',
     POWER: 'OPPHØYD.I',
+    PROPER: 'STOR.FORBOKSTAV',
     RADIANS: 'RADIANER',
     RAND: 'TILFELDIG',
     ROUND: 'AVRUND',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index fa2415880e..8c333759c7 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'OF',
     PI: 'PI',
     POWER: 'MACHT',
+    PROPER: 'BEGINLETTERS',
     RADIANS: 'RADIALEN',
     RAND: 'ASELECT',
     ROUND: 'AFRONDEN',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index bcd18afcd4..44dec549d4 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'LUB',
     PI: 'PI',
     POWER: 'POTĘGA',
+    PROPER: 'Z.WIELKIEJ.LITERY',
     RADIANS: 'RADIANY',
     RAND: 'LOSUJ',
     ROUND: 'ZAOKR',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index ef8540ef26..fbcb04821f 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'OU',
     PI: 'PI',
     POWER: 'POTÊNCIA',
+    PROPER: 'PRI.MAIÚSCULA',
     RADIANS: 'RADIANOS',
     RAND: 'ALEATÓRIO',
     ROUND: 'ARRED',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index b302d70876..c5daf7eb81 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'ИЛИ',
     PI: 'ПИ',
     POWER: 'СТЕПЕНЬ',
+    PROPER: 'ПРОПНАЧ',
     RADIANS: 'РАДИАНЫ',
     RAND: 'СЛЧИС',
     ROUND: 'ОКРУГЛ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 1a3d4068d4..48887de6da 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'ELLER',
     PI: 'PI',
     POWER: 'UPPHÖJT.TILL',
+    PROPER: 'INITIAL',
     RADIANS: 'RADIANER',
     RAND: 'SLUMP',
     ROUND: 'AVRUNDA',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index b65d012e51..a761d88782 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -101,6 +101,7 @@ const dictionary: RawTranslationPackage = {
     OR: 'VEYA',
     PI: 'Pİ',
     POWER: 'KUVVET',
+    PROPER: 'YAZIM.DÜZENİ',
     RADIANS: 'RADYAN',
     RAND: 'S_SAYI_ÜRET',
     ROUND: 'YUVARLA',
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 4fb0a97e62..e16f393050 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -24,6 +24,9 @@ export class TextPlugin extends FunctionPlugin {
     },
     'TRIM': {
       method: 'trim'
+    },
+    'PROPER': {
+      method: 'proper'
     }
   }
 
@@ -102,4 +105,10 @@ export class TextPlugin extends FunctionPlugin {
       return arg.replace(/^ +| +$/g, '').replace(/ +/g, ' ')
     })
   }
+
+  public proper(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
+      return arg.replace(/\w\S*/g, word => word.charAt(0).toUpperCase() + word.substr(1).toLowerCase())
+    })
+  }
 }
diff --git a/test/interpreter/function-proper.spec.ts b/test/interpreter/function-proper.spec.ts
new file mode 100644
index 0000000000..0765b6f441
--- /dev/null
+++ b/test/interpreter/function-proper.spec.ts
@@ -0,0 +1,40 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function PROPER', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=PROPER()'],
+      ['=PROPER("foo", "bar")']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should work', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=PROPER("foo")'],
+      ['=PROPER("foo bar")'],
+      ['=PROPER(" foo    bar   ")'],
+      ['=PROPER("fOo BAR")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('Foo')
+    expect(engine.getCellValue(adr('A2'))).toEqual('Foo Bar')
+    expect(engine.getCellValue(adr('A3'))).toEqual(' Foo    Bar   ')
+    expect(engine.getCellValue(adr('A4'))).toEqual('Foo Bar')
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=PROPER(1)'],
+      ['=PROPER(5+5)'],
+      ['=PROPER(TRUE())'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('1')
+    expect(engine.getCellValue(adr('A2'))).toEqual('10')
+    expect(engine.getCellValue(adr('A3'))).toEqual('True')
+  })
+})
\ No newline at end of file

From b934922fe66fafe2d4848014aea7e6e601225771 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Sat, 27 Jun 2020 10:42:27 +0200
Subject: [PATCH 04/97] CLEAN function

---
 src/i18n/languages/csCZ.ts              |  1 +
 src/i18n/languages/daDK.ts              |  1 +
 src/i18n/languages/deDE.ts              |  1 +
 src/i18n/languages/enGB.ts              |  1 +
 src/i18n/languages/esES.ts              |  1 +
 src/i18n/languages/fiFI.ts              |  1 +
 src/i18n/languages/frFR.ts              |  1 +
 src/i18n/languages/huHU.ts              |  1 +
 src/i18n/languages/itIT.ts              |  1 +
 src/i18n/languages/nbNO.ts              |  1 +
 src/i18n/languages/nlNL.ts              |  1 +
 src/i18n/languages/plPL.ts              |  1 +
 src/i18n/languages/ptPT.ts              |  1 +
 src/i18n/languages/ruRU.ts              |  1 +
 src/i18n/languages/svSE.ts              |  1 +
 src/i18n/languages/trTR.ts              |  1 +
 src/interpreter/plugin/TextPlugin.ts    | 10 ++++++
 test/interpreter/function-clean.spec.ts | 47 +++++++++++++++++++++++++
 18 files changed, 73 insertions(+)
 create mode 100644 test/interpreter/function-clean.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index b538ad0f96..30a963ed82 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'ZAOKR.NAHORU',
     CHAR: 'ZNAK',
     CHOOSE: 'ZVOLIT',
+    CLEAN: 'VYČISTIT',
     CODE: 'KÓD',
     COLUMNS: 'SLOUPCE',
     CONCATENATE: 'CONCATENATE',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 3d1dd7acfa..74e80729fe 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'AFRUND.LOFT',
     CHAR: 'CHAR',
     CHOOSE: 'VÆLG',
+    CLEAN: 'RENS',
     CODE: 'KODE',
     COLUMNS: 'KOLONNER',
     CONCATENATE: 'SAMMENKÆDNING',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 87d7532ac0..a62ad0105d 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'OBERGRENZE',
     CHAR: 'ZEICHEN',
     CHOOSE: 'WAHL',
+    CLEAN: 'SÄUBERN',
     CODE: 'CODE',
     COLUMNS: 'SPALTEN',
     CONCATENATE: 'VERKETTEN',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index f1356aae78..e2cd117605 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'CEILING',
     CHAR: 'CHAR',
     CHOOSE: 'CHOOSE',
+    CLEAN: 'CLEAN',
     CODE: 'CODE',
     COLUMNS: 'COLUMNS',
     CONCATENATE: 'CONCATENATE',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 8d34609374..08b15e2d8b 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -39,6 +39,7 @@ export const dictionary: RawTranslationPackage = {
     CEILING: 'MULTIPLO.SUPERIOR',
     CHAR: 'CARACTER',
     CHOOSE: 'ELEGIR',
+    CLEAN: 'LIMPIAR',
     CODE: 'CODIGO',
     COLUMNS: 'COLUMNAS',
     CONCATENATE: 'CONCATENAR',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index fdf70fc27f..e7180e596e 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'PYÖRISTÄ.KERR.YLÖS',
     CHAR: 'MERKKI',
     CHOOSE: 'VALITSE.INDEKSI',
+    CLEAN: 'SIIVOA',
     CODE: 'KOODI',
     COLUMNS: 'SARAKKEET',
     CONCATENATE: 'KETJUTA',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 5a86324768..205d942c34 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'PLAFOND',
     CHAR: 'CAR',
     CHOOSE: 'CHOISIR',
+    CLEAN: 'EPURAGE',
     CODE: 'CODE',
     COLUMNS: 'COLONNES',
     CONCATENATE: 'CONCATENER',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index af29147d87..aa3a19b0ce 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'PLAFON',
     CHAR: 'KARAKTER',
     CHOOSE: 'VÁLASZT',
+    CLEAN: 'TISZTÍT',
     CODE: 'KÓD',
     COLUMNS: 'OSZLOPOK',
     CONCATENATE: 'ÖSSZEFŰZ',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index d0d693746e..f9d194c60b 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'ARROTONDA.ECCESSO',
     CHAR: 'CODICE.CARATT',
     CHOOSE: 'SCEGLI',
+    CLEAN: 'LIBERA',
     CODE: 'CODICE',
     COLUMNS: 'COLONNE',
     CONCATENATE: 'CONCATENA',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 0c877ea383..8537f073b1 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'AVRUND.GJELDENDE.MULTIPLUM',
     CHAR: 'TEGNKODE',
     CHOOSE: 'VELG',
+    CLEAN: 'RENSK',
     CODE: 'KODE',
     COLUMNS: 'KOLONNER',
     CONCATENATE: 'KJEDE.SAMMEN',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index 8c333759c7..48a56f5770 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'AFRONDEN.BOVEN',
     CHAR: 'TEKEN',
     CHOOSE: 'KIEZEN',
+    CLEAN: 'WISSEN.CONTROL',
     CODE: 'CODE',
     COLUMNS: 'KOLOMMEN',
     CONCATENATE: 'TEKST.SAMENVOEGEN',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index 44dec549d4..f840475780 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'ZAOKR.W.GÓRĘ',
     CHAR: 'ZNAK',
     CHOOSE: 'WYBIERZ',
+    CLEAN: 'OCZYŚĆ',
     CODE: 'KOD',
     COLUMNS: 'LICZBA.KOLUMN',
     CONCATENATE: 'ZŁĄCZ.TEKST',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index fbcb04821f..89f0d57865 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'TETO',
     CHAR: 'CARACT',
     CHOOSE: 'ESCOLHER',
+    CLEAN: 'TIRAR',
     CODE: 'CÓDIGO',
     COLUMNS: 'COLS',
     CONCATENATE: 'CONCATENAR',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index c5daf7eb81..82d5bfc1fe 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'ОКРВВЕРХ',
     CHAR: 'СИМВОЛ',
     CHOOSE: 'ВЫБОР',
+    CLEAN: 'ПЕЧСИМВ',
     CODE: 'КОДСИМВ',
     COLUMNS: 'ЧИСЛСТОЛБ',
     CONCATENATE: 'СЦЕПИТЬ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 48887de6da..9bdd7953ff 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'RUNDA.UPP',
     CHAR: 'TECKENKOD',
     CHOOSE: 'VÄLJ',
+    CLEAN: 'STÄDA',
     CODE: 'KOD',
     COLUMNS: 'KOLUMNER',
     CONCATENATE: 'SAMMANFOGA',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index a761d88782..0f90a98a9c 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -39,6 +39,7 @@ const dictionary: RawTranslationPackage = {
     CEILING: 'TAVANAYUVARLA',
     CHAR: 'DAMGA',
     CHOOSE: 'ELEMAN',
+    CLEAN: 'TEMİZ',
     CODE: 'KOD',
     COLUMNS: 'SÜTUNSAY',
     CONCATENATE: 'BİRLEŞTİR',
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index e16f393050..553eedc6e3 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -27,6 +27,9 @@ export class TextPlugin extends FunctionPlugin {
     },
     'PROPER': {
       method: 'proper'
+    },
+    'CLEAN': {
+      method: 'clean'
     }
   }
 
@@ -111,4 +114,11 @@ export class TextPlugin extends FunctionPlugin {
       return arg.replace(/\w\S*/g, word => word.charAt(0).toUpperCase() + word.substr(1).toLowerCase())
     })
   }
+
+  public clean(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
+      // eslint-disable-next-line no-control-regex
+      return arg.replace(/[\u0000-\u001F]/g, '')
+    })
+  }
 }
diff --git a/test/interpreter/function-clean.spec.ts b/test/interpreter/function-clean.spec.ts
new file mode 100644
index 0000000000..65333029de
--- /dev/null
+++ b/test/interpreter/function-clean.spec.ts
@@ -0,0 +1,47 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function CLEAN', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=CLEAN()'],
+      ['=CLEAN("foo", "bar")']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should work', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=CLEAN("foo\u0000")'],
+      ['=CLEAN("foo\u0020")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('foo')
+    expect(engine.getCellValue(adr('A2'))).toEqual('foo\u0020')
+  })
+
+  it('should clean all non-printable ASCII characters', () => {
+    const str = Array.from(Array(32).keys()).map(code => String.fromCharCode(code)).join('')
+
+    const engine = HyperFormula.buildFromArray([
+      [str, '=LEN(A1)', '=CLEAN(A1)'],
+    ])
+
+    expect(engine.getCellValue(adr('B1'))).toEqual(32)
+    expect(engine.getCellValue(adr('C1'))).toEqual('')
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=CLEAN(1)'],
+      ['=CLEAN(5+5)'],
+      ['=CLEAN(TRUE())'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('1')
+    expect(engine.getCellValue(adr('A2'))).toEqual('10')
+    expect(engine.getCellValue(adr('A3'))).toEqual('TRUE')
+  })
+})
\ No newline at end of file

From e2228f2c3d6fedc66e65502dbc5d10b73f7b8737 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Sat, 27 Jun 2020 12:18:43 +0200
Subject: [PATCH 05/97] REPT function

---
 src/i18n/languages/csCZ.ts               |  1 +
 src/i18n/languages/daDK.ts               |  1 +
 src/i18n/languages/deDE.ts               |  1 +
 src/i18n/languages/enGB.ts               |  1 +
 src/i18n/languages/esES.ts               |  1 +
 src/i18n/languages/fiFI.ts               |  1 +
 src/i18n/languages/frFR.ts               |  1 +
 src/i18n/languages/huHU.ts               |  1 +
 src/i18n/languages/itIT.ts               |  1 +
 src/i18n/languages/nbNO.ts               |  1 +
 src/i18n/languages/nlNL.ts               |  1 +
 src/i18n/languages/plPL.ts               |  1 +
 src/i18n/languages/ptPT.ts               |  1 +
 src/i18n/languages/ruRU.ts               |  1 +
 src/i18n/languages/svSE.ts               |  1 +
 src/i18n/languages/trTR.ts               |  1 +
 src/interpreter/plugin/FunctionPlugin.ts | 45 ++++++++++--------
 src/interpreter/plugin/TextPlugin.ts     | 15 ++++++
 test/interpreter/function-rept.spec.ts   | 58 ++++++++++++++++++++++++
 19 files changed, 114 insertions(+), 20 deletions(-)
 create mode 100644 test/interpreter/function-rept.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 30a963ed82..1fbd25774a 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'VELKÁ2',
     RADIANS: 'RADIANS',
     RAND: 'NÁHČÍSLO',
+    REPT: 'OPAKOVAT',
     ROUND: 'ZAOKROUHLIT',
     ROUNDDOWN: 'ROUNDDOWN',
     ROUNDUP: 'ROUNDUP',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 74e80729fe..3d51bc5de0 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'STORT.FORBOGSTAV',
     RADIANS: 'RADIANER',
     RAND: 'SLUMP',
+    REPT: 'GENTAG',
     ROUND: 'AFRUND',
     ROUNDDOWN: 'RUND.NED',
     ROUNDUP: 'RUND.OP',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index a62ad0105d..ff146b71e4 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'GROSS2',
     RADIANS: 'BOGENMASS',
     RAND: 'ZUFALLSZAHL',
+    REPT: 'WIEDERHOLEN',
     ROUND: 'RUNDEN',
     ROUNDDOWN: 'ABRUNDEN',
     ROUNDUP: 'AUFRUNDEN',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index e2cd117605..3c6bd085ca 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'PROPER',
     RADIANS: 'RADIANS',
     RAND: 'RAND',
+    REPT: 'REPT',
     ROUND: 'ROUND',
     ROUNDDOWN: 'ROUNDDOWN',
     ROUNDUP: 'ROUNDUP',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 08b15e2d8b..695ff52a41 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -105,6 +105,7 @@ export const dictionary: RawTranslationPackage = {
     PROPER: 'NOMPROPIO',
     RADIANS: 'RADIANES',
     RAND: 'ALEATORIO',
+    REPT: 'REPETIR',
     ROUND: 'REDONDEAR',
     ROUNDDOWN: 'REDONDEAR.MENOS',
     ROUNDUP: 'REDONDEAR.MAS',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index e7180e596e..0b2ed05f04 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'ERISNIMI',
     RADIANS: 'RADIAANIT',
     RAND: 'SATUNNAISLUKU',
+    REPT: 'TOISTA',
     ROUND: 'PYÖRISTÄ',
     ROUNDDOWN: 'PYÖRISTÄ.DES.ALAS',
     ROUNDUP: 'PYÖRISTÄ.DES.YLÖS',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 205d942c34..b965f75fe8 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'NOMPROPRE',
     RADIANS: 'RADIANS',
     RAND: 'ALEA',
+    REPT: 'REPT',
     ROUND: 'ARRONDI',
     ROUNDDOWN: 'ARRONDI.INF',
     ROUNDUP: 'ARRONDI.SUP',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index aa3a19b0ce..de47fd36ee 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'TNÉV',
     RADIANS: 'RADIÁN',
     RAND: 'VÉL',
+    REPT: 'SOKSZOR',
     ROUND: 'KEREKÍTÉS',
     ROUNDDOWN: 'KEREK.LE',
     ROUNDUP: 'KEREK.FEL',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index f9d194c60b..cda0463313 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'MAIUSC.INIZ',
     RADIANS: 'RADIANTI',
     RAND: 'CASUALE',
+    REPT: 'RIPETI',
     ROUND: 'ARROTONDA',
     ROUNDDOWN: 'ARROTONDA.PER.DIF',
     ROUNDUP: 'ARROTONDA.PER.ECC',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 8537f073b1..217b399863 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'STOR.FORBOKSTAV',
     RADIANS: 'RADIANER',
     RAND: 'TILFELDIG',
+    REPT: 'GJENTA',
     ROUND: 'AVRUND',
     ROUNDDOWN: 'AVRUND.NED',
     ROUNDUP: 'AVRUND.OPP',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index 48a56f5770..d8cb165bef 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'BEGINLETTERS',
     RADIANS: 'RADIALEN',
     RAND: 'ASELECT',
+    REPT: 'HERHALING',
     ROUND: 'AFRONDEN',
     ROUNDDOWN: 'AFRONDEN.NAAR.BENEDEN',
     ROUNDUP: 'AFRONDEN.NAAR.BOVEN',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index f840475780..e2f2f75da1 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'Z.WIELKIEJ.LITERY',
     RADIANS: 'RADIANY',
     RAND: 'LOSUJ',
+    REPT: 'POWT',
     ROUND: 'ZAOKR',
     ROUNDDOWN: 'ZAOKR.DÓŁ',
     ROUNDUP: 'ZAOKR.GÓRA',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 89f0d57865..a87bc10331 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'PRI.MAIÚSCULA',
     RADIANS: 'RADIANOS',
     RAND: 'ALEATÓRIO',
+    REPT: 'REPT',
     ROUND: 'ARRED',
     ROUNDDOWN: 'ARREDONDAR.PARA.BAIXO',
     ROUNDUP: 'ARREDONDAR.PARA.CIMA',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 82d5bfc1fe..4b586626db 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'ПРОПНАЧ',
     RADIANS: 'РАДИАНЫ',
     RAND: 'СЛЧИС',
+    REPT: 'ПОВТОР',
     ROUND: 'ОКРУГЛ',
     ROUNDDOWN: 'ОКРУГЛВНИЗ',
     ROUNDUP: 'ОКРУГЛВВЕРХ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 9bdd7953ff..d5a98588c6 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'INITIAL',
     RADIANS: 'RADIANER',
     RAND: 'SLUMP',
+    REPT: 'REP',
     ROUND: 'AVRUNDA',
     ROUNDDOWN: 'AVRUNDA.NEDÅT',
     ROUNDUP: 'AVRUNDA.UPPÅT',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 0f90a98a9c..7113f4218d 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -105,6 +105,7 @@ const dictionary: RawTranslationPackage = {
     PROPER: 'YAZIM.DÜZENİ',
     RADIANS: 'RADYAN',
     RAND: 'S_SAYI_ÜRET',
+    REPT: 'YİNELE',
     ROUND: 'YUVARLA',
     ROUNDDOWN: 'AŞAĞIYUVARLA',
     ROUNDUP: 'YUKARIYUVARLA',
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index c8f8b00a91..6e4d1d3634 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -25,7 +25,8 @@ export interface FunctionMetadata {
 }
 
 export interface FunctionPluginDefinition {
-  new (interpreter: Interpreter): FunctionPlugin,
+  new(interpreter: Interpreter): FunctionPlugin,
+
   implementedFunctions: ImplementedFunctions,
 }
 
@@ -81,11 +82,11 @@ export abstract class FunctionPlugin {
   }
 
   protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-    return this.templateWithOneArgumentCoercion(ast, formulaAddress, (arg: InternalScalarValue) => this.coerceScalarToNumberOrError(arg), fn)
+    return this.coerceArguments(ast, formulaAddress, [this.coerceScalarToNumberOrError], fn)
   }
 
   protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.templateWithOneArgumentCoercion(ast, formulaAddress, coerceScalarToString, fn)
+    return this.coerceArguments(ast, formulaAddress, [coerceScalarToString], fn)
   }
 
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
@@ -138,32 +139,36 @@ export abstract class FunctionPlugin {
     return value
   }
 
-  protected coerceScalarToNumberOrError(arg: InternalScalarValue): number | CellError {
-    return this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
-  }
+  protected coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
-  private templateWithOneArgumentCoercion(
+  protected coerceArguments = (
     ast: ProcedureAst,
     formulaAddress: SimpleCellAddress,
-    coerceFunction: (arg: InternalScalarValue) => InternalScalarValue,
-    fn: (arg: any) => InternalScalarValue,
-  ) {
-    if (ast.args.length !== 1) {
+    coerceFunctions: ((arg: InternalScalarValue) => InternalScalarValue)[],
+    fn: (...arg: any) => InternalScalarValue,
+  ) => {
+    const numberOfArguments = coerceFunctions.length
+
+    if (ast.args.length !== numberOfArguments) {
       return new CellError(ErrorType.NA)
     }
     if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
       return new CellError(ErrorType.NUM)
     }
 
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const coercedArg = coerceFunction(arg)
-    if (coercedArg instanceof CellError) {
-      return coercedArg
-    } else {
-      return fn(coercedArg)
+    const coercedArguments: InternalScalarValue[] = []
+    for (let i = 0; i < ast.args.length; ++i) {
+      const arg = this.evaluateAst(ast.args[i], formulaAddress)
+      if (arg instanceof SimpleRangeValue) {
+        return new CellError(ErrorType.VALUE)
+      }
+      const coercedArg = coerceFunctions[i](arg)
+      if (coercedArg instanceof CellError) {
+        return coercedArg
+      }
+      coercedArguments.push(coercedArg)
     }
+
+    return fn(...coercedArguments)
   }
 }
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 553eedc6e3..ab7fd4238e 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -30,6 +30,9 @@ export class TextPlugin extends FunctionPlugin {
     },
     'CLEAN': {
       method: 'clean'
+    },
+    'REPT': {
+      method: 'rept'
     }
   }
 
@@ -121,4 +124,16 @@ export class TextPlugin extends FunctionPlugin {
       return arg.replace(/[\u0000-\u001F]/g, '')
     })
   }
+
+  public rept(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.coerceArguments(ast, formulaAddress, [
+      coerceScalarToString,
+      this.coerceScalarToNumberOrError
+    ], (text: string, count: number) => {
+      if (count < 0) {
+        return new CellError(ErrorType.VALUE)
+      }
+      return text.repeat(count)
+    })
+  }
 }
diff --git a/test/interpreter/function-rept.spec.ts b/test/interpreter/function-rept.spec.ts
new file mode 100644
index 0000000000..35a508e1c9
--- /dev/null
+++ b/test/interpreter/function-rept.spec.ts
@@ -0,0 +1,58 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function REPT', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=REPT()'],
+      ['=REPT("foo")'],
+      ['=REPT("foo", 1, 2)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should return VALUE when wrong type of second parameter', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=REPT("foo", "bar")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should return VALUE when second parameter is less than 0', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=REPT("foo", -1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should work', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=REPT("foo", 0)'],
+      ['=REPT("foo", 3)'],
+      ['=REPT(1, 5)'],
+      ['=REPT("Na", 7)&" Batman!"'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('')
+    expect(engine.getCellValue(adr('A2'))).toEqual('foofoofoo')
+    expect(engine.getCellValue(adr('A3'))).toEqual('11111')
+    expect(engine.getCellValue(adr('A4'))).toEqual('NaNaNaNaNaNaNa Batman!')
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=REPT(1, 1)'],
+      ['=REPT(5+5, 1)'],
+      ['=REPT(TRUE(), 1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('1')
+    expect(engine.getCellValue(adr('A2'))).toEqual('10')
+    expect(engine.getCellValue(adr('A3'))).toEqual('TRUE')
+  })
+})
\ No newline at end of file

From 760d49e78c021069d9060ed2440e7f7d1a3f5b90 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Mon, 29 Jun 2020 13:01:43 +0200
Subject: [PATCH 06/97] More general method for coercion with defaults

---
 src/interpreter/Interpreter.ts           | 11 ++++++++--
 src/interpreter/plugin/FunctionPlugin.ts | 27 ++++++++++++++++++------
 test/interpreter/function-rept.spec.ts   |  4 +++-
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/src/interpreter/Interpreter.ts b/src/interpreter/Interpreter.ts
index 605d5d8013..d092ec27f9 100644
--- a/src/interpreter/Interpreter.ts
+++ b/src/interpreter/Interpreter.ts
@@ -5,7 +5,14 @@
 
 import GPU from 'gpu.js'
 import {AbsoluteCellRange, AbsoluteColumnRange, AbsoluteRowRange} from '../AbsoluteCellRange'
-import {CellError, ErrorType, InternalNoErrorCellValue, invalidSimpleCellAddress, SimpleCellAddress} from '../Cell'
+import {
+  CellError,
+  EmptyValue,
+  ErrorType,
+  InternalNoErrorCellValue,
+  invalidSimpleCellAddress,
+  SimpleCellAddress
+} from '../Cell'
 import {ColumnSearchStrategy} from '../ColumnSearch/ColumnSearchStrategy'
 import {Config} from '../Config'
 import {DateTimeHelper} from '../DateTimeHelper'
@@ -52,7 +59,7 @@ export class Interpreter {
   public evaluateAst(ast: Ast, formulaAddress: SimpleCellAddress): InterpreterValue {
     switch (ast.type) {
       case AstNodeType.EMPTY: {
-        throw new Error('Empty argument should not be evaluated.')
+        return EmptyValue
       }
       case AstNodeType.CELL_REFERENCE: {
         const address = ast.reference.toSimpleCellAddress(formulaAddress)
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 6e4d1d3634..c4b9eb6024 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -12,6 +12,7 @@ import {Ast, AstNodeType, ProcedureAst} from '../../parser'
 import {coerceScalarToString} from '../ArithmeticHelper'
 import {Interpreter} from '../Interpreter'
 import {InterpreterValue, SimpleRangeValue} from '../InterpreterValue'
+import {Maybe} from '../../Maybe'
 
 export interface ImplementedFunctions {
   [formulaId: string]: FunctionMetadata,
@@ -147,18 +148,23 @@ export abstract class FunctionPlugin {
     coerceFunctions: ((arg: InternalScalarValue) => InternalScalarValue)[],
     fn: (...arg: any) => InternalScalarValue,
   ) => {
-    const numberOfArguments = coerceFunctions.length
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, coerceFunctions, [], fn)
+  }
 
-    if (ast.args.length !== numberOfArguments) {
+  protected coerceArgumentsWithDefaults = (
+    args: Ast[],
+    formulaAddress: SimpleCellAddress,
+    coerceFunctions: ((arg: InternalScalarValue) => InternalScalarValue)[],
+    defaults: Maybe<InternalScalarValue>[],
+    fn: (...arg: any) => InternalScalarValue
+  ) => {
+    if (args.length > coerceFunctions.length) {
       return new CellError(ErrorType.NA)
     }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
 
     const coercedArguments: InternalScalarValue[] = []
-    for (let i = 0; i < ast.args.length; ++i) {
-      const arg = this.evaluateAst(ast.args[i], formulaAddress)
+    for (let i = 0; i < coerceFunctions.length; ++i) {
+      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], defaults[i])
       if (arg instanceof SimpleRangeValue) {
         return new CellError(ErrorType.VALUE)
       }
@@ -171,4 +177,11 @@ export abstract class FunctionPlugin {
 
     return fn(...coercedArguments)
   }
+
+  protected evaluateArgOrDefault = (formulaAddress: SimpleCellAddress, argAst?: Ast, defaultValue?: InternalScalarValue): InterpreterValue => {
+    if (argAst !== undefined) {
+      return this.evaluateAst(argAst, formulaAddress)
+    }
+    return defaultValue || new CellError(ErrorType.NA)
+  }
 }
diff --git a/test/interpreter/function-rept.spec.ts b/test/interpreter/function-rept.spec.ts
index 35a508e1c9..335710c093 100644
--- a/test/interpreter/function-rept.spec.ts
+++ b/test/interpreter/function-rept.spec.ts
@@ -35,13 +35,15 @@ describe('Function REPT', () => {
       ['=REPT("foo", 0)'],
       ['=REPT("foo", 3)'],
       ['=REPT(1, 5)'],
+      ['=REPT(, 5)'],
       ['=REPT("Na", 7)&" Batman!"'],
     ])
 
     expect(engine.getCellValue(adr('A1'))).toEqual('')
     expect(engine.getCellValue(adr('A2'))).toEqual('foofoofoo')
     expect(engine.getCellValue(adr('A3'))).toEqual('11111')
-    expect(engine.getCellValue(adr('A4'))).toEqual('NaNaNaNaNaNaNa Batman!')
+    expect(engine.getCellValue(adr('A4'))).toEqual('')
+    expect(engine.getCellValue(adr('A5'))).toEqual('NaNaNaNaNaNaNa Batman!')
   })
 
   it('should coerce other types to string', () => {

From 674e02d9a5cb962fc5a80e7f8144440bdf78d0e3 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Mon, 29 Jun 2020 13:27:18 +0200
Subject: [PATCH 07/97] RIGHT function

---
 src/i18n/languages/csCZ.ts              |  1 +
 src/i18n/languages/daDK.ts              |  1 +
 src/i18n/languages/deDE.ts              |  1 +
 src/i18n/languages/enGB.ts              |  1 +
 src/i18n/languages/esES.ts              |  1 +
 src/i18n/languages/fiFI.ts              |  1 +
 src/i18n/languages/frFR.ts              |  1 +
 src/i18n/languages/huHU.ts              |  1 +
 src/i18n/languages/itIT.ts              |  1 +
 src/i18n/languages/nbNO.ts              |  1 +
 src/i18n/languages/nlNL.ts              |  1 +
 src/i18n/languages/plPL.ts              |  1 +
 src/i18n/languages/ptPT.ts              |  1 +
 src/i18n/languages/ruRU.ts              |  1 +
 src/i18n/languages/svSE.ts              |  1 +
 src/i18n/languages/trTR.ts              |  1 +
 src/interpreter/plugin/TextPlugin.ts    | 20 +++++++
 test/interpreter/function-right.spec.ts | 76 +++++++++++++++++++++++++
 18 files changed, 112 insertions(+)
 create mode 100644 test/interpreter/function-right.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 1fbd25774a..cefcffd6c0 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANS',
     RAND: 'NÁHČÍSLO',
     REPT: 'OPAKOVAT',
+    RIGHT: 'ZPRAVA',
     ROUND: 'ZAOKROUHLIT',
     ROUNDDOWN: 'ROUNDDOWN',
     ROUNDUP: 'ROUNDUP',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 3d51bc5de0..ee35a65ea4 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANER',
     RAND: 'SLUMP',
     REPT: 'GENTAG',
+    RIGHT: 'HØJRE',
     ROUND: 'AFRUND',
     ROUNDDOWN: 'RUND.NED',
     ROUNDUP: 'RUND.OP',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index ff146b71e4..b1d61f68d8 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'BOGENMASS',
     RAND: 'ZUFALLSZAHL',
     REPT: 'WIEDERHOLEN',
+    RIGHT: 'RECHTS',
     ROUND: 'RUNDEN',
     ROUNDDOWN: 'ABRUNDEN',
     ROUNDUP: 'AUFRUNDEN',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 3c6bd085ca..c5e67ba544 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANS',
     RAND: 'RAND',
     REPT: 'REPT',
+    RIGHT: 'RIGHT',
     ROUND: 'ROUND',
     ROUNDDOWN: 'ROUNDDOWN',
     ROUNDUP: 'ROUNDUP',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 695ff52a41..5b8ec0965e 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -106,6 +106,7 @@ export const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANES',
     RAND: 'ALEATORIO',
     REPT: 'REPETIR',
+    RIGHT: 'DERECHA',
     ROUND: 'REDONDEAR',
     ROUNDDOWN: 'REDONDEAR.MENOS',
     ROUNDUP: 'REDONDEAR.MAS',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 0b2ed05f04..0cb39a9c23 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIAANIT',
     RAND: 'SATUNNAISLUKU',
     REPT: 'TOISTA',
+    RIGHT: 'OIKEA',
     ROUND: 'PYÖRISTÄ',
     ROUNDDOWN: 'PYÖRISTÄ.DES.ALAS',
     ROUNDUP: 'PYÖRISTÄ.DES.YLÖS',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index b965f75fe8..74a5c3f976 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANS',
     RAND: 'ALEA',
     REPT: 'REPT',
+    RIGHT: 'DROITE',
     ROUND: 'ARRONDI',
     ROUNDDOWN: 'ARRONDI.INF',
     ROUNDUP: 'ARRONDI.SUP',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index de47fd36ee..13951f5c32 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIÁN',
     RAND: 'VÉL',
     REPT: 'SOKSZOR',
+    RIGHT: 'JOBB',
     ROUND: 'KEREKÍTÉS',
     ROUNDDOWN: 'KEREK.LE',
     ROUNDUP: 'KEREK.FEL',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index cda0463313..1bb4ae10f8 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANTI',
     RAND: 'CASUALE',
     REPT: 'RIPETI',
+    RIGHT: 'DESTRA',
     ROUND: 'ARROTONDA',
     ROUNDDOWN: 'ARROTONDA.PER.DIF',
     ROUNDUP: 'ARROTONDA.PER.ECC',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 217b399863..69104d9032 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANER',
     RAND: 'TILFELDIG',
     REPT: 'GJENTA',
+    RIGHT: 'HØYRE',
     ROUND: 'AVRUND',
     ROUNDDOWN: 'AVRUND.NED',
     ROUNDUP: 'AVRUND.OPP',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index d8cb165bef..04ea02c56d 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIALEN',
     RAND: 'ASELECT',
     REPT: 'HERHALING',
+    RIGHT: 'RECHTS',
     ROUND: 'AFRONDEN',
     ROUNDDOWN: 'AFRONDEN.NAAR.BENEDEN',
     ROUNDUP: 'AFRONDEN.NAAR.BOVEN',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index e2f2f75da1..b61d938e34 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANY',
     RAND: 'LOSUJ',
     REPT: 'POWT',
+    RIGHT: 'PRAWY',
     ROUND: 'ZAOKR',
     ROUNDDOWN: 'ZAOKR.DÓŁ',
     ROUNDUP: 'ZAOKR.GÓRA',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index a87bc10331..cea818aa63 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANOS',
     RAND: 'ALEATÓRIO',
     REPT: 'REPT',
+    RIGHT: 'DIREITA',
     ROUND: 'ARRED',
     ROUNDDOWN: 'ARREDONDAR.PARA.BAIXO',
     ROUNDUP: 'ARREDONDAR.PARA.CIMA',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 4b586626db..8e28a03e43 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'РАДИАНЫ',
     RAND: 'СЛЧИС',
     REPT: 'ПОВТОР',
+    RIGHT: 'ПРАВСИМВ',
     ROUND: 'ОКРУГЛ',
     ROUNDDOWN: 'ОКРУГЛВНИЗ',
     ROUNDUP: 'ОКРУГЛВВЕРХ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index d5a98588c6..f273097ec2 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADIANER',
     RAND: 'SLUMP',
     REPT: 'REP',
+    RIGHT: 'HÖGER',
     ROUND: 'AVRUNDA',
     ROUNDDOWN: 'AVRUNDA.NEDÅT',
     ROUNDUP: 'AVRUNDA.UPPÅT',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 7113f4218d..3660d56594 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -106,6 +106,7 @@ const dictionary: RawTranslationPackage = {
     RADIANS: 'RADYAN',
     RAND: 'S_SAYI_ÜRET',
     REPT: 'YİNELE',
+    RIGHT: 'SAĞ',
     ROUND: 'YUVARLA',
     ROUNDDOWN: 'AŞAĞIYUVARLA',
     ROUNDUP: 'YUKARIYUVARLA',
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index ab7fd4238e..06607b52c6 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -33,6 +33,9 @@ export class TextPlugin extends FunctionPlugin {
     },
     'REPT': {
       method: 'rept'
+    },
+    'RIGHT': {
+      method: 'right'
     }
   }
 
@@ -136,4 +139,21 @@ export class TextPlugin extends FunctionPlugin {
       return text.repeat(count)
     })
   }
+
+  public right(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
+      coerceScalarToString,
+      this.coerceScalarToNumberOrError
+    ], [
+      undefined,
+      1
+    ], (text: string, lenght: number) => {
+      if (lenght < 0) {
+        return new CellError(ErrorType.VALUE)
+      } else if (lenght === 0) {
+        return ''
+      }
+      return text.slice(-lenght)
+    })
+  }
 }
diff --git a/test/interpreter/function-right.spec.ts b/test/interpreter/function-right.spec.ts
new file mode 100644
index 0000000000..67253d82fd
--- /dev/null
+++ b/test/interpreter/function-right.spec.ts
@@ -0,0 +1,76 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function RIGHT', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=RIGHT()'],
+      ['=RIGHT("foo", 1, 2)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should return VALUE when wrong type of second parameter', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=RIGHT("foo", "bar")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should work with empty argument', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=RIGHT(, 1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('')
+  })
+
+  it('should return one character by default', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=RIGHT("bar")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('r')
+  })
+
+  it('should return VALUE when second parameter is less than 0', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=RIGHT("foo", -1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should work', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=RIGHT("", 4)'],
+      ['=RIGHT("bar", 0)'],
+      ['=RIGHT("bar", 1)'],
+      ['=RIGHT("bar", 3)'],
+      ['=RIGHT("bar", 4)'],
+      ['=RIGHT(123, 2)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('')
+    expect(engine.getCellValue(adr('A2'))).toEqual('')
+    expect(engine.getCellValue(adr('A3'))).toEqual('r')
+    expect(engine.getCellValue(adr('A4'))).toEqual('bar')
+    expect(engine.getCellValue(adr('A5'))).toEqual('bar')
+    expect(engine.getCellValue(adr('A6'))).toEqual('23')
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=RIGHT(1, 1)'],
+      ['=RIGHT(5+5, 1)'],
+      ['=RIGHT(TRUE(), 1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('1')
+    expect(engine.getCellValue(adr('A2'))).toEqual('0')
+    expect(engine.getCellValue(adr('A3'))).toEqual('E')
+  })
+})
\ No newline at end of file

From 11e0d1b06bae79dc72fcda087f65ade90db34f10 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Mon, 29 Jun 2020 13:38:59 +0200
Subject: [PATCH 08/97] LEFT function

---
 src/i18n/languages/csCZ.ts             |  1 +
 src/i18n/languages/daDK.ts             |  1 +
 src/i18n/languages/deDE.ts             |  1 +
 src/i18n/languages/enGB.ts             |  1 +
 src/i18n/languages/esES.ts             |  1 +
 src/i18n/languages/fiFI.ts             |  1 +
 src/i18n/languages/frFR.ts             |  1 +
 src/i18n/languages/huHU.ts             |  1 +
 src/i18n/languages/itIT.ts             |  1 +
 src/i18n/languages/nbNO.ts             |  1 +
 src/i18n/languages/nlNL.ts             |  1 +
 src/i18n/languages/plPL.ts             |  1 +
 src/i18n/languages/ptPT.ts             |  1 +
 src/i18n/languages/ruRU.ts             |  1 +
 src/i18n/languages/svSE.ts             |  1 +
 src/i18n/languages/trTR.ts             |  1 +
 src/interpreter/plugin/TextPlugin.ts   | 18 ++++++
 test/interpreter/function-left.spec.ts | 76 ++++++++++++++++++++++++++
 18 files changed, 110 insertions(+)
 create mode 100644 test/interpreter/function-left.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index cefcffd6c0..b90fbdfd4c 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'JE.ČISLO',
     ISODD: 'ISODD',
     ISTEXT: 'JE.TEXT',
+    LEFT: 'ZLEVA',
     LEN: 'DÉLKA',
     LN: 'LN',
     LOG: 'LOGZ',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index ee35a65ea4..f5dfed8ead 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ER.TAL',
     ISODD: 'ER.ULIGE',
     ISTEXT: 'ER.TEKST',
+    LEFT: 'VENSTRE',
     LEN: 'LÆNGDE',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index b1d61f68d8..d99cd57cb3 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ISTZAHL',
     ISODD: 'ISTUNGERADE',
     ISTEXT: 'ISTTEXT',
+    LEFT: 'LINKS',
     LEN: 'LÄNGE',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index c5e67ba544..0c80d537bc 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ISNUMBER',
     ISODD: 'ISODD',
     ISTEXT: 'ISTEXT',
+    LEFT: 'LEFT',
     LEN: 'LEN',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 5b8ec0965e..f15dc3a1e6 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -81,6 +81,7 @@ export const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ESNUMERO',
     ISODD: 'ES.IMPAR',
     ISTEXT: 'ESTEXTO',
+    LEFT: 'IZQUIERDA',
     LEN: 'LARGO',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 0cb39a9c23..870229ebe6 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ONLUKU',
     ISODD: 'ONPARITON',
     ISTEXT: 'ONTEKSTI',
+    LEFT: 'VASEN',
     LEN: 'PITUUS',
     LN: 'LUONNLOG',
     LOG: 'LOG',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 74a5c3f976..f65557e518 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ESTNUM',
     ISODD: 'EST.IMPAIR',
     ISTEXT: 'ESTTEXTE',
+    LEFT: 'GAUCHE',
     LEN: 'NBCAR',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 13951f5c32..dd75f35f26 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'SZÁM',
     ISODD: 'PÁRATLANE',
     ISTEXT: 'SZÖVEG.E',
+    LEFT: 'BAL',
     LEN: 'HOSSZ',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 1bb4ae10f8..f5068823bf 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'VAL.NUMERO',
     ISODD: 'VAL.DISPARI',
     ISTEXT: 'VAL.TESTO',
+    LEFT: 'SINISTRA',
     LEN: 'LUNGHEZZA',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 69104d9032..f37c165148 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ERTALL',
     ISODD: 'ERODDE',
     ISTEXT: 'ERTEKST',
+    LEFT: 'VENSTRE',
     LEN: 'LENGDE',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index 04ea02c56d..b1f388f7e3 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ISGETAL',
     ISODD: 'IS.ONEVEN',
     ISTEXT: 'ISTEKST',
+    LEFT: 'LINKS',
     LEN: 'PITUUS',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index b61d938e34..17f32645ac 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'CZY.LICZBA',
     ISODD: 'CZY.NIEPARZYSTE',
     ISTEXT: 'CZY.TEKST',
+    LEFT: 'LEWY',
     LEN: 'DŁ',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index cea818aa63..8ca8e9ebef 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ÉNÚM',
     ISODD: 'ÉIMPAR',
     ISTEXT: 'ÉTEXTO',
+    LEFT: 'ESQUERDA',
     LEN: 'NÚM.CARACT',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 8e28a03e43..a5e30198a0 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ЕЧИСЛО',
     ISODD: 'ЕНЕЧЁТ',
     ISTEXT: 'ЕТЕКСТ',
+    LEFT: 'ЛЕВСИМВ',
     LEN: 'ДЛСТР',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index f273097ec2..e5b9d4c2df 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ÄRTAL',
     ISODD: 'ÄRUDDA',
     ISTEXT: 'ÄRTEXT',
+    LEFT: 'VÄNSTER',
     LEN: 'LÄNGD',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 3660d56594..5a20d2bc77 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -81,6 +81,7 @@ const dictionary: RawTranslationPackage = {
     ISNUMBER: 'ESAYIYSA',
     ISODD: 'TEKMİ',
     ISTEXT: 'EMETİNSE',
+    LEFT: 'SOL',
     LEN: 'UZUNLUK',
     LN: 'LN',
     LOG: 'LOG',
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 06607b52c6..792d815bb2 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -36,6 +36,9 @@ export class TextPlugin extends FunctionPlugin {
     },
     'RIGHT': {
       method: 'right'
+    },
+    'LEFT': {
+      method: 'left'
     }
   }
 
@@ -156,4 +159,19 @@ export class TextPlugin extends FunctionPlugin {
       return text.slice(-lenght)
     })
   }
+
+  public left(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
+      coerceScalarToString,
+      this.coerceScalarToNumberOrError
+    ], [
+      undefined,
+      1
+    ], (text: string, lenght: number) => {
+      if (lenght < 0) {
+        return new CellError(ErrorType.VALUE)
+      }
+      return text.slice(0, lenght)
+    })
+  }
 }
diff --git a/test/interpreter/function-left.spec.ts b/test/interpreter/function-left.spec.ts
new file mode 100644
index 0000000000..4b6ca364a9
--- /dev/null
+++ b/test/interpreter/function-left.spec.ts
@@ -0,0 +1,76 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function LEFT', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEFT()'],
+      ['=LEFT("foo", 1, 2)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should return VALUE when wrong type of second parameter', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEFT("foo", "bar")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should work with empty argument', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEFT(, 1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('')
+  })
+
+  it('should return one character by default', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEFT("bar")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('b')
+  })
+
+  it('should return VALUE when second parameter is less than 0', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEFT("foo", -1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should work', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEFT("", 4)'],
+      ['=LEFT("bar", 0)'],
+      ['=LEFT("bar", 1)'],
+      ['=LEFT("bar", 3)'],
+      ['=LEFT("bar", 4)'],
+      ['=LEFT(123, 2)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('')
+    expect(engine.getCellValue(adr('A2'))).toEqual('')
+    expect(engine.getCellValue(adr('A3'))).toEqual('b')
+    expect(engine.getCellValue(adr('A4'))).toEqual('bar')
+    expect(engine.getCellValue(adr('A5'))).toEqual('bar')
+    expect(engine.getCellValue(adr('A6'))).toEqual('12')
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=LEFT(1, 1)'],
+      ['=LEFT(5+5, 1)'],
+      ['=LEFT(TRUE(), 1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual('1')
+    expect(engine.getCellValue(adr('A2'))).toEqual('1')
+    expect(engine.getCellValue(adr('A3'))).toEqual('T')
+  })
+})
\ No newline at end of file

From 292dac4111ae4f984c9fad5283e782f94078bd47 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Tue, 30 Jun 2020 19:06:15 +0200
Subject: [PATCH 09/97] Fix typo

---
 src/interpreter/plugin/TextPlugin.ts | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 792d815bb2..043d022b04 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -150,13 +150,13 @@ export class TextPlugin extends FunctionPlugin {
     ], [
       undefined,
       1
-    ], (text: string, lenght: number) => {
-      if (lenght < 0) {
+    ], (text: string, length: number) => {
+      if (length < 0) {
         return new CellError(ErrorType.VALUE)
-      } else if (lenght === 0) {
+      } else if (length === 0) {
         return ''
       }
-      return text.slice(-lenght)
+      return text.slice(-length)
     })
   }
 
@@ -167,11 +167,11 @@ export class TextPlugin extends FunctionPlugin {
     ], [
       undefined,
       1
-    ], (text: string, lenght: number) => {
-      if (lenght < 0) {
+    ], (text: string, length: number) => {
+      if (length < 0) {
         return new CellError(ErrorType.VALUE)
       }
-      return text.slice(0, lenght)
+      return text.slice(0, length)
     })
   }
 }

From e616628600ba1e983ffd9706448029dfa5737725 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Tue, 30 Jun 2020 19:58:16 +0200
Subject: [PATCH 10/97] SEARCH function

---
 src/i18n/languages/csCZ.ts               |   1 +
 src/i18n/languages/daDK.ts               |   1 +
 src/i18n/languages/deDE.ts               |   1 +
 src/i18n/languages/enGB.ts               |   1 +
 src/i18n/languages/esES.ts               |   1 +
 src/i18n/languages/fiFI.ts               |   1 +
 src/i18n/languages/frFR.ts               |   1 +
 src/i18n/languages/huHU.ts               |   1 +
 src/i18n/languages/itIT.ts               |   1 +
 src/i18n/languages/nbNO.ts               |   1 +
 src/i18n/languages/nlNL.ts               |   1 +
 src/i18n/languages/plPL.ts               |   1 +
 src/i18n/languages/ptPT.ts               |   1 +
 src/i18n/languages/ruRU.ts               |   1 +
 src/i18n/languages/svSE.ts               |   1 +
 src/i18n/languages/trTR.ts               |   1 +
 src/interpreter/ArithmeticHelper.ts      |  10 ++-
 src/interpreter/plugin/TextPlugin.ts     |  31 +++++++
 test/interpreter/function-search.spec.ts | 108 +++++++++++++++++++++++
 19 files changed, 163 insertions(+), 2 deletions(-)
 create mode 100644 test/interpreter/function-search.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index b90fbdfd4c..807a1a3540 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'ROUNDDOWN',
     ROUNDUP: 'ROUNDUP',
     ROWS: 'ŘÁDKY',
+    SEARCH: 'HLEDAT',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'ODMOCNINA',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index f5dfed8ead..5ea8818c3b 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'RUND.NED',
     ROUNDUP: 'RUND.OP',
     ROWS: 'RÆKKER',
+    SEARCH: 'SØG',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'KVROD',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index d99cd57cb3..756bea0360 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'ABRUNDEN',
     ROUNDUP: 'AUFRUNDEN',
     ROWS: 'ZEILEN',
+    SEARCH: 'SUCHEN',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'WURZEL',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 0c80d537bc..ea7cc88ea0 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'ROUNDDOWN',
     ROUNDUP: 'ROUNDUP',
     ROWS: 'ROWS',
+    SEARCH: 'SEARCH',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'SQRT',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index f15dc3a1e6..d8b14d0408 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -112,6 +112,7 @@ export const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'REDONDEAR.MENOS',
     ROUNDUP: 'REDONDEAR.MAS',
     ROWS: 'FILAS',
+    SEARCH: 'HALLAR',
     SIN: 'SENO',
     SPLIT: 'SPLIT',
     SQRT: 'RAIZ',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 870229ebe6..2a2ae2bf53 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'PYÖRISTÄ.DES.ALAS',
     ROUNDUP: 'PYÖRISTÄ.DES.YLÖS',
     ROWS: 'RIVIT',
+    SEARCH: 'KÄY.LÄPI',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'NELIÖJUURI',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index f65557e518..2f29e2e68d 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'ARRONDI.INF',
     ROUNDUP: 'ARRONDI.SUP',
     ROWS: 'LIGNES',
+    SEARCH: 'CHERCHE',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'RACINE',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index dd75f35f26..268e5a1d5e 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'KEREK.LE',
     ROUNDUP: 'KEREK.FEL',
     ROWS: 'SOROK',
+    SEARCH: 'SZÖVEG.KERES',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'GYÖK',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index f5068823bf..95e3b67c89 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'ARROTONDA.PER.DIF',
     ROUNDUP: 'ARROTONDA.PER.ECC',
     ROWS: 'RIGHE',
+    SEARCH: 'RICERCA',
     SIN: 'SEN',
     SPLIT: 'SPLIT',
     SQRT: 'RADQ',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index f37c165148..ab5439ca51 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'AVRUND.NED',
     ROUNDUP: 'AVRUND.OPP',
     ROWS: 'RADER',
+    SEARCH: 'SØK',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'ROT',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index b1f388f7e3..c9b24b18a3 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'AFRONDEN.NAAR.BENEDEN',
     ROUNDUP: 'AFRONDEN.NAAR.BOVEN',
     ROWS: 'RIJEN',
+    SEARCH: 'VIND.SPEC',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'WORTEL',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index 17f32645ac..d576abf02f 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'ZAOKR.DÓŁ',
     ROUNDUP: 'ZAOKR.GÓRA',
     ROWS: 'ILE.WIERSZY',
+    SEARCH: 'SZUKAJ.TEKST',
     SIN: 'SIN',
     SPLIT: 'PODZIEL.TEKST',
     SQRT: 'PIERWIASTEK',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 8ca8e9ebef..865650ec34 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'ARREDONDAR.PARA.BAIXO',
     ROUNDUP: 'ARREDONDAR.PARA.CIMA',
     ROWS: 'LINS',
+    SEARCH: 'LOCALIZAR',
     SIN: 'SEN',
     SPLIT: 'SPLIT',
     SQRT: 'RAIZ',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index a5e30198a0..f59c51a889 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'ОКРУГЛВНИЗ',
     ROUNDUP: 'ОКРУГЛВВЕРХ',
     ROWS: 'ЧСТРОК',
+    SEARCH: 'ПОИСК',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'КОРЕНЬ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index e5b9d4c2df..b6a7b3d2e1 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'AVRUNDA.NEDÅT',
     ROUNDUP: 'AVRUNDA.UPPÅT',
     ROWS: 'RADER',
+    SEARCH: 'SÖK',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'ROT',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 5a20d2bc77..8dda35c289 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -112,6 +112,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDDOWN: 'AŞAĞIYUVARLA',
     ROUNDUP: 'YUKARIYUVARLA',
     ROWS: 'SATIRSAY',
+    SEARCH: 'MBUL',
     SIN: 'SİN',
     SPLIT: 'SPLIT',
     SQRT: 'KAREKÖK',
diff --git a/src/interpreter/ArithmeticHelper.ts b/src/interpreter/ArithmeticHelper.ts
index 04000f6341..7e6908ad6c 100644
--- a/src/interpreter/ArithmeticHelper.ts
+++ b/src/interpreter/ArithmeticHelper.ts
@@ -44,6 +44,12 @@ export class ArithmeticHelper {
     }
   }
 
+  public searchString(pattern: string, text: string): number {
+    const regexp = this.buildRegex(pattern, false)
+    const result = regexp.exec(text)
+    return result?.index ?? -1
+  }
+
   public requiresRegex(pattern: string): boolean {
     if(!this.config.useRegularExpresssions && !this.config.useWildcards) {
       return !this.config.matchWholeCell
@@ -57,7 +63,7 @@ export class ArithmeticHelper {
     return false
   }
 
-  private buildRegex(pattern: string): RegExp {
+  private buildRegex(pattern: string, matchWholeCell: boolean = true): RegExp {
     pattern = this.normalizeString(pattern)
     let regexpStr
     let useWildcards = this.config.useWildcards
@@ -77,7 +83,7 @@ export class ArithmeticHelper {
     } else {
       regexpStr = escapeAllCharacters(pattern, this.config.caseSensitive)
     }
-    if(this.config.matchWholeCell) {
+    if(this.config.matchWholeCell && matchWholeCell) {
       return RegExp('^('+ regexpStr + ')$')
     } else {
       return RegExp(regexpStr)
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 043d022b04..fe28d638ea 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -39,6 +39,9 @@ export class TextPlugin extends FunctionPlugin {
     },
     'LEFT': {
       method: 'left'
+    },
+    'SEARCH': {
+      method: 'search'
     }
   }
 
@@ -174,4 +177,32 @@ export class TextPlugin extends FunctionPlugin {
       return text.slice(0, length)
     })
   }
+
+  public search(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
+      coerceScalarToString,
+      coerceScalarToString,
+      this.coerceScalarToNumberOrError
+    ], [
+      undefined,
+      undefined,
+      1
+    ], (pattern, text: string, startIndex: number) => {
+      if (startIndex < 1 || startIndex > text.length) {
+        return new CellError(ErrorType.VALUE)
+      }
+
+      const normalizedText = text.substr(startIndex - 1).toLowerCase()
+
+      let index: number
+      if (this.interpreter.arithmeticHelper.requiresRegex(pattern)) {
+        index = this.interpreter.arithmeticHelper.searchString(pattern, normalizedText)
+      } else {
+        index = normalizedText.indexOf(pattern.toLowerCase())
+      }
+
+      index = index + startIndex
+      return index > 0 ? index : new CellError(ErrorType.VALUE)
+    })
+  }
 }
diff --git a/test/interpreter/function-search.spec.ts b/test/interpreter/function-search.spec.ts
new file mode 100644
index 0000000000..31cfdd52c5
--- /dev/null
+++ b/test/interpreter/function-search.spec.ts
@@ -0,0 +1,108 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function SEARCH', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=SEARCH()'],
+      ['=SEARCH("foo")'],
+      ['=SEARCH("foo", 1, 2, 3)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should return VALUE when wrong type of third parameter', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=SEARCH("foo", "bar", "baz")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should return VALUE if third parameter is not between 1 and text length', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=SEARCH("foo", "bar", 0)'],
+      ['=SEARCH("foo", "bar", -1)'],
+      ['=SEARCH("foo", "bar", 4)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should work with simple strings', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=SEARCH("f", "foo")'],
+      ['=SEARCH("o", "foo")'],
+      ['=SEARCH("o", "foo", 3)'],
+      ['=SEARCH("g", "foo")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A2'))).toEqual(2)
+    expect(engine.getCellValue(adr('A3'))).toEqual(3)
+    expect(engine.getCellValue(adr('A4'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should work with wildcards', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=SEARCH("*f", "foobarbaz")'],
+      ['=SEARCH("b*b", "foobarbaz")'],
+      ['=SEARCH("b?z", "foobarbaz")'],
+      ['=SEARCH("b?b", "foobarbaz")'],
+      ['=SEARCH("?b", "foobarbaz", 5)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A2'))).toEqual(4)
+    expect(engine.getCellValue(adr('A3'))).toEqual(7)
+    expect(engine.getCellValue(adr('A4'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A5'))).toEqual(6)
+  })
+
+  it('should work with regular expressions', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=SEARCH(".*f", "foobarbaz")'],
+      ['=SEARCH("b.*b", "foobarbaz")'],
+      ['=SEARCH("b.z", "foobarbaz")'],
+      ['=SEARCH("b.b", "foobarbaz")'],
+      ['=SEARCH(".b", "foobarbaz", 5)'],
+    ], { useRegularExpresssions: true })
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A2'))).toEqual(4)
+    expect(engine.getCellValue(adr('A3'))).toEqual(7)
+    expect(engine.getCellValue(adr('A4'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A5'))).toEqual(6)
+  })
+
+  it('should be case insensitive', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=SEARCH("R", "bar")'],
+      ['=SEARCH("r", "baR")'],
+      ['=SEARCH("?R", "bar")'],
+      ['=SEARCH("*r", "baR")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(3)
+    expect(engine.getCellValue(adr('A2'))).toEqual(3)
+    expect(engine.getCellValue(adr('A3'))).toEqual(2)
+    expect(engine.getCellValue(adr('A4'))).toEqual(1)
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=SEARCH(1, 1, 1)'],
+      ['=SEARCH(0, 5+5)'],
+      ['=SEARCH("U", TRUE())'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A2'))).toEqual(2)
+    expect(engine.getCellValue(adr('A3'))).toEqual(3)
+  })
+})
\ No newline at end of file

From 06a83a91fe3e38a663c906292a7e4c6891711935 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Tue, 30 Jun 2020 20:03:24 +0200
Subject: [PATCH 11/97] FIND function

---
 src/i18n/languages/csCZ.ts             |  1 +
 src/i18n/languages/daDK.ts             |  1 +
 src/i18n/languages/deDE.ts             |  1 +
 src/i18n/languages/enGB.ts             |  1 +
 src/i18n/languages/esES.ts             |  1 +
 src/i18n/languages/fiFI.ts             |  1 +
 src/i18n/languages/frFR.ts             |  1 +
 src/i18n/languages/huHU.ts             |  1 +
 src/i18n/languages/itIT.ts             |  1 +
 src/i18n/languages/nbNO.ts             |  1 +
 src/i18n/languages/nlNL.ts             |  1 +
 src/i18n/languages/plPL.ts             |  1 +
 src/i18n/languages/ptPT.ts             |  1 +
 src/i18n/languages/ruRU.ts             |  1 +
 src/i18n/languages/svSE.ts             |  1 +
 src/i18n/languages/trTR.ts             |  1 +
 src/interpreter/plugin/TextPlugin.ts   | 24 ++++++++
 test/interpreter/function-find.spec.ts | 80 ++++++++++++++++++++++++++
 18 files changed, 120 insertions(+)
 create mode 100644 test/interpreter/function-find.spec.ts

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 807a1a3540..5a9ea44498 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'ZAOKROUHLIT.NA.SUDÉ',
     EXP: 'EXP',
     FALSE: 'NEPRAVDA',
+    FIND: 'NAJÍT',
     IF: 'KDYŽ',
     IFERROR: 'IFERROR',
     IFNA: 'IFNA',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 5ea8818c3b..42533a25ca 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'LIGE',
     EXP: 'EKSP',
     FALSE: 'FALSE',
+    FIND: 'FIND',
     IF: 'HVIS',
     IFERROR: 'HVIS.FEJL',
     IFNA: 'HVISIT',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 756bea0360..6f3228547b 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'GERADE',
     EXP: 'EXP',
     FALSE: 'FALSCH',
+    FIND: 'FINDEN',
     IF: 'WENN',
     IFERROR: 'WENNFEHLER',
     IFNA: 'WENNNV',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index ea7cc88ea0..6b259115c3 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'EVEN',
     EXP: 'EXP',
     FALSE: 'FALSE',
+    FIND: 'FIND',
     IF: 'IF',
     IFERROR: 'IFERROR',
     IFNA: 'IFNA',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index d8b14d0408..85c9b3fc88 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -68,6 +68,7 @@ export const dictionary: RawTranslationPackage = {
     EVEN: 'REDONDEA.PAR',
     EXP: 'EXP',
     FALSE: 'FALSO',
+    FIND: 'ENCONTRAR',
     IF: 'SI',
     IFERROR: 'SI.ERROR',
     IFNA: 'IFNA',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 2a2ae2bf53..179f52870a 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'PARILLINEN',
     EXP: 'EKSPONENTTI',
     FALSE: 'EPÄTOSI',
+    FIND: 'ETSI',
     IF: 'JOS',
     IFERROR: 'JOSVIRHE',
     IFNA: 'JOSPUUTTUU',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 2f29e2e68d..0c0cdd76f1 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'PAIR',
     EXP: 'EXP',
     FALSE: 'FAUX',
+    FIND: 'TROUVE',
     IF: 'SI',
     IFERROR: 'SIERREUR',
     IFNA: 'SI.NON.DISP',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 268e5a1d5e..e6e256eec8 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'PÁROS',
     EXP: 'KITEVŐ',
     FALSE: 'HAMIS',
+    FIND: 'SZÖVEG.TALÁL',
     IF: 'HA',
     IFERROR: 'HAHIBA',
     IFNA: 'HAHIÁNYZIK',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 95e3b67c89..ab30e4a621 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'PARI',
     EXP: 'EXP',
     FALSE: 'FALSO',
+    FIND: 'TROVA',
     IF: 'SE',
     IFERROR: 'SE.ERRORE',
     IFNA: 'SE.NON.DISP.',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index ab5439ca51..dad06fd788 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'AVRUND.TIL.PARTALL',
     EXP: 'EKSP',
     FALSE: 'USANN',
+    FIND: 'FINN',
     IF: 'HVIS',
     IFERROR: 'HVISFEIL',
     IFNA: 'HVIS.IT',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index c9b24b18a3..e7539646d1 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'EVEN',
     EXP: 'EXP',
     FALSE: 'ONWAAR',
+    FIND: 'VIND.ALLES',
     IF: 'ALS',
     IFERROR: 'ALS.FOUT',
     IFNA: 'ALS.NB',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index d576abf02f..458650fdff 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'ZAOKR.DO.PARZ',
     EXP: 'EXP',
     FALSE: 'FAŁSZ',
+    FIND: 'ZNAJDŹ',
     IF: 'JEŻELI',
     IFERROR: 'JEŻELI.BŁĄD',
     IFNA: 'JEŻELI.ND',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 865650ec34..66ec685dcf 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'PAR',
     EXP: 'EXP',
     FALSE: 'FALSO',
+    FIND: 'PROCURAR',
     IF: 'SE',
     IFERROR: 'SEERRO',
     IFNA: 'SENA',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index f59c51a889..f62b9058bb 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'ЧЁТН',
     EXP: 'EXP',
     FALSE: 'ЛОЖЬ',
+    FIND: 'НАЙТИ',
     IF: 'ЕСЛИ',
     IFERROR: 'ЕСЛИОШИБКА',
     IFNA: 'ЕСНД',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index b6a7b3d2e1..52865fcd76 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'JÄMN',
     EXP: 'EXP',
     FALSE: 'FALSKT',
+    FIND: 'HITTA',
     IF: 'OM',
     IFERROR: 'OMFEL',
     IFNA: 'IFNA',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 8dda35c289..7fa5ad112e 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -68,6 +68,7 @@ const dictionary: RawTranslationPackage = {
     EVEN: 'ÇİFT',
     EXP: 'ÜS',
     FALSE: 'YANLIŞ',
+    FIND: 'BUL',
     IF: 'EĞER',
     IFERROR: 'EĞERHATA',
     IFNA: 'EĞERYOKSA',
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index fe28d638ea..4e6d728f02 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -42,6 +42,9 @@ export class TextPlugin extends FunctionPlugin {
     },
     'SEARCH': {
       method: 'search'
+    },
+    'FIND': {
+      method: 'find'
     }
   }
 
@@ -205,4 +208,25 @@ export class TextPlugin extends FunctionPlugin {
       return index > 0 ? index : new CellError(ErrorType.VALUE)
     })
   }
+
+  public find(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
+      coerceScalarToString,
+      coerceScalarToString,
+      this.coerceScalarToNumberOrError
+    ], [
+      undefined,
+      undefined,
+      1
+    ], (pattern, text: string, startIndex: number) => {
+      if (startIndex < 1 || startIndex > text.length) {
+        return new CellError(ErrorType.VALUE)
+      }
+
+      const shiftedText = text.substr(startIndex - 1)
+      const index = shiftedText.indexOf(pattern) + startIndex
+
+      return index > 0 ? index : new CellError(ErrorType.VALUE)
+    })
+  }
 }
diff --git a/test/interpreter/function-find.spec.ts b/test/interpreter/function-find.spec.ts
new file mode 100644
index 0000000000..8dbf6e4c90
--- /dev/null
+++ b/test/interpreter/function-find.spec.ts
@@ -0,0 +1,80 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function FIND', () => {
+  it('should return N/A when number of arguments is incorrect', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=FIND()'],
+      ['=FIND("foo")'],
+      ['=FIND("foo", 1, 2, 3)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should return VALUE when wrong type of third parameter', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=FIND("foo", "bar", "baz")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should return VALUE if third parameter is not between 1 and text length', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=FIND("foo", "bar", 0)'],
+      ['=FIND("foo", "bar", -1)'],
+      ['=FIND("foo", "bar", 4)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should work', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=FIND("f", "foo")'],
+      ['=FIND("o", "foo")'],
+      ['=FIND("o", "foo", 3)'],
+      ['=FIND("g", "foo")'],
+      ['=FIND("?o", "?o")'],
+      ['=FIND("?o", "oo")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A2'))).toEqual(2)
+    expect(engine.getCellValue(adr('A3'))).toEqual(3)
+    expect(engine.getCellValue(adr('A4'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A5'))).toEqual(1)
+    expect(engine.getCellValue(adr('A6'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should be case sensitive', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=FIND("R", "bar")'],
+      ['=FIND("r", "bar")'],
+      ['=FIND("r", "baR")'],
+      ['=FIND("R", "baR")'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A2'))).toEqual(3)
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A4'))).toEqual(3)
+  })
+
+  it('should coerce other types to string', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=FIND(1, 1, 1)'],
+      ['=FIND(0, 5+5)'],
+      ['=FIND("U", TRUE())'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A2'))).toEqual(2)
+    expect(engine.getCellValue(adr('A3'))).toEqual(3)
+  })
+})
\ No newline at end of file

From 01b284660028be8f0c368f4a9ad23974b6acbea2 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Tue, 30 Jun 2020 20:17:21 +0200
Subject: [PATCH 12/97] Introduce FunctionArgumentDefinition

---
 src/index.ts                             |  3 +-
 src/interpreter/index.ts                 |  9 +++++-
 src/interpreter/plugin/FunctionPlugin.ts | 29 +++++++----------
 src/interpreter/plugin/TextPlugin.ts     | 40 ++++++++----------------
 4 files changed, 35 insertions(+), 46 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 7b3de7c062..abf206947b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -50,7 +50,7 @@ import {
   UnableToParseError
 } from './errors'
 import * as plugins from './interpreter/plugin'
-import {FunctionPluginDefinition, FunctionPlugin} from './interpreter'
+import {FunctionArgumentDefinition, FunctionPlugin, FunctionPluginDefinition} from './interpreter'
 import {ColumnRowIndex} from './CrudOperations'
 
 /** @internal */
@@ -121,6 +121,7 @@ export {
   ColumnRowIndex,
   RawTranslationPackage,
   FunctionPluginDefinition,
+  FunctionArgumentDefinition,
   NamedExpression,
   NamedExpressionOptions,
   HyperFormula,
diff --git a/src/interpreter/index.ts b/src/interpreter/index.ts
index bc6b7a182b..bfd9c517a9 100644
--- a/src/interpreter/index.ts
+++ b/src/interpreter/index.ts
@@ -3,11 +3,18 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {FunctionMetadata, FunctionPluginDefinition, ImplementedFunctions, FunctionPlugin} from './plugin/FunctionPlugin'
+import {
+  FunctionArgumentDefinition,
+  FunctionMetadata,
+  FunctionPlugin,
+  FunctionPluginDefinition,
+  ImplementedFunctions
+} from './plugin/FunctionPlugin'
 import {FunctionTranslationsPackage} from './FunctionRegistry'
 
 export { 
   FunctionPluginDefinition,
+  FunctionArgumentDefinition,
   FunctionPlugin,
   ImplementedFunctions,
   FunctionMetadata,
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index c4b9eb6024..ddc80c3f3a 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -31,6 +31,11 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
+export interface FunctionArgumentDefinition {
+  typeCoercionFunction: (arg: InternalScalarValue) => InternalScalarValue,
+  defaultValue?: InternalScalarValue,
+}
+
 export type PluginFunctionType = (ast: ProcedureAst, formulaAddress: SimpleCellAddress) => InternalScalarValue
 
 /**
@@ -83,11 +88,11 @@ export abstract class FunctionPlugin {
   }
 
   protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArguments(ast, formulaAddress, [this.coerceScalarToNumberOrError], fn)
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ typeCoercionFunction: this.coerceScalarToNumberOrError }], fn)
   }
 
   protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArguments(ast, formulaAddress, [coerceScalarToString], fn)
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ typeCoercionFunction: coerceScalarToString }], fn)
   }
 
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
@@ -142,33 +147,23 @@ export abstract class FunctionPlugin {
 
   protected coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
-  protected coerceArguments = (
-    ast: ProcedureAst,
-    formulaAddress: SimpleCellAddress,
-    coerceFunctions: ((arg: InternalScalarValue) => InternalScalarValue)[],
-    fn: (...arg: any) => InternalScalarValue,
-  ) => {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, coerceFunctions, [], fn)
-  }
-
   protected coerceArgumentsWithDefaults = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
-    coerceFunctions: ((arg: InternalScalarValue) => InternalScalarValue)[],
-    defaults: Maybe<InternalScalarValue>[],
+    argumentDefinitions: FunctionArgumentDefinition[],
     fn: (...arg: any) => InternalScalarValue
   ) => {
-    if (args.length > coerceFunctions.length) {
+    if (args.length > argumentDefinitions.length) {
       return new CellError(ErrorType.NA)
     }
 
     const coercedArguments: InternalScalarValue[] = []
-    for (let i = 0; i < coerceFunctions.length; ++i) {
-      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], defaults[i])
+    for (let i = 0; i < argumentDefinitions.length; ++i) {
+      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
       if (arg instanceof SimpleRangeValue) {
         return new CellError(ErrorType.VALUE)
       }
-      const coercedArg = coerceFunctions[i](arg)
+      const coercedArg = argumentDefinitions[i].typeCoercionFunction(arg)
       if (coercedArg instanceof CellError) {
         return coercedArg
       }
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 4e6d728f02..d91606df5b 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -138,9 +138,9 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public rept(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArguments(ast, formulaAddress, [
-      coerceScalarToString,
-      this.coerceScalarToNumberOrError
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
+      { typeCoercionFunction: coerceScalarToString },
+      { typeCoercionFunction: this.coerceScalarToNumberOrError },
     ], (text: string, count: number) => {
       if (count < 0) {
         return new CellError(ErrorType.VALUE)
@@ -151,11 +151,8 @@ export class TextPlugin extends FunctionPlugin {
 
   public right(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      coerceScalarToString,
-      this.coerceScalarToNumberOrError
-    ], [
-      undefined,
-      1
+      { typeCoercionFunction: coerceScalarToString },
+      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
     ], (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
@@ -168,11 +165,8 @@ export class TextPlugin extends FunctionPlugin {
 
   public left(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      coerceScalarToString,
-      this.coerceScalarToNumberOrError
-    ], [
-      undefined,
-      1
+      { typeCoercionFunction: coerceScalarToString },
+      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
     ], (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
@@ -183,13 +177,9 @@ export class TextPlugin extends FunctionPlugin {
 
   public search(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      coerceScalarToString,
-      coerceScalarToString,
-      this.coerceScalarToNumberOrError
-    ], [
-      undefined,
-      undefined,
-      1
+      { typeCoercionFunction: coerceScalarToString },
+      { typeCoercionFunction: coerceScalarToString },
+      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
     ], (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
@@ -211,13 +201,9 @@ export class TextPlugin extends FunctionPlugin {
 
   public find(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      coerceScalarToString,
-      coerceScalarToString,
-      this.coerceScalarToNumberOrError
-    ], [
-      undefined,
-      undefined,
-      1
+      { typeCoercionFunction: coerceScalarToString },
+      { typeCoercionFunction: coerceScalarToString },
+      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
     ], (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)

From 83e6c4c83a7d1a1ce2e6efc4812301c80de27e47 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Wed, 1 Jul 2020 09:43:13 +0200
Subject: [PATCH 13/97] Align with develop

---
 test/interpreter/function-search.spec.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/interpreter/function-search.spec.ts b/test/interpreter/function-search.spec.ts
index 31cfdd52c5..027de54bda 100644
--- a/test/interpreter/function-search.spec.ts
+++ b/test/interpreter/function-search.spec.ts
@@ -71,7 +71,7 @@ describe('Function SEARCH', () => {
       ['=SEARCH("b.z", "foobarbaz")'],
       ['=SEARCH("b.b", "foobarbaz")'],
       ['=SEARCH(".b", "foobarbaz", 5)'],
-    ], { useRegularExpresssions: true })
+    ], { useRegularExpressions: true })
 
     expect(engine.getCellValue(adr('A1'))).toEqual(1)
     expect(engine.getCellValue(adr('A2'))).toEqual(4)

From 9c02db49b965053006b3f41c5da750dcebe48b4b Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Tue, 21 Jul 2020 00:47:26 +0200
Subject: [PATCH 14/97] string types

---
 src/interpreter/plugin/FunctionPlugin.ts | 20 ++++++--
 src/interpreter/plugin/TextPlugin.ts     | 59 +++++++++++++-----------
 2 files changed, 47 insertions(+), 32 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index ddc80c3f3a..302016a07a 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -31,8 +31,10 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
+export type ArgumentTypes = "string" | "number"
+
 export interface FunctionArgumentDefinition {
-  typeCoercionFunction: (arg: InternalScalarValue) => InternalScalarValue,
+  argumentType: string,
   defaultValue?: InternalScalarValue,
 }
 
@@ -88,11 +90,11 @@ export abstract class FunctionPlugin {
   }
 
   protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ typeCoercionFunction: this.coerceScalarToNumberOrError }], fn)
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ argumentType: "number"}], fn)
   }
 
   protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ typeCoercionFunction: coerceScalarToString }], fn)
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ argumentType: "string" }], fn)
   }
 
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
@@ -145,8 +147,16 @@ export abstract class FunctionPlugin {
     return value
   }
 
-  protected coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
+  public coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
+  public coerceToType(arg: InternalScalarValue, coercedType: ArgumentTypes): InternalScalarValue {
+    switch(coercedType) {
+      case 'number':
+        return this.coerceScalarToNumberOrError(arg)
+      case 'string':
+        return coerceScalarToString(arg)
+    }
+  }
   protected coerceArgumentsWithDefaults = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
@@ -163,7 +173,7 @@ export abstract class FunctionPlugin {
       if (arg instanceof SimpleRangeValue) {
         return new CellError(ErrorType.VALUE)
       }
-      const coercedArg = argumentDefinitions[i].typeCoercionFunction(arg)
+      const coercedArg = this.coerceToType(arg, argumentDefinitions[i].argumentType as ArgumentTypes)
       if (coercedArg instanceof CellError) {
         return coercedArg
       }
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index d91606df5b..21e03a3db5 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -32,19 +32,41 @@ export class TextPlugin extends FunctionPlugin {
       method: 'clean'
     },
     'REPT': {
-      method: 'rept'
+      method: 'rept',
+      parameters: [
+        { argumentType: "string" },
+        { argumentType: "number" },
+      ],
     },
     'RIGHT': {
-      method: 'right'
+      method: 'right',
+      parameters: [
+        { argumentType: "string" },
+        { argumentType: "number", defaultValue: 1 },
+      ],
     },
     'LEFT': {
-      method: 'left'
+      method: 'left',
+      parameters: [
+        { argumentType: "string" },
+        { argumentType: "number", defaultValue: 1 },
+      ],
     },
     'SEARCH': {
-      method: 'search'
+      method: 'search',
+      parameters: [
+        { argumentType: "string" },
+        { argumentType: "string" },
+        { argumentType: "number", defaultValue: 1 },
+      ],
     },
     'FIND': {
-      method: 'find'
+      method: 'find',
+      parameters: [
+        { argumentType: "string" },
+        { argumentType: "string" },
+        { argumentType: "number", defaultValue: 1 },
+      ],
     }
   }
 
@@ -138,10 +160,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public rept(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError },
-    ], (text: string, count: number) => {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.REPT.parameters, (text: string, count: number) => {
       if (count < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -150,10 +169,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public right(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
-    ], (text: string, length: number) => {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.RIGHT.parameters, (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       } else if (length === 0) {
@@ -164,10 +180,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public left(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
-    ], (text: string, length: number) => {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.LEFT.parameters, (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -176,11 +189,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public search(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
-    ], (pattern, text: string, startIndex: number) => {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.SEARCH.parameters, (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }
@@ -200,11 +209,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public find(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
-    ], (pattern, text: string, startIndex: number) => {
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.FIND.parameters, (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }

From eaaae5e58ea3ad64968f38749f7d60a7dd8142f9 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Tue, 21 Jul 2020 00:49:51 +0200
Subject: [PATCH 15/97] linter

---
 src/interpreter/plugin/FunctionPlugin.ts |  6 +++---
 src/interpreter/plugin/TextPlugin.ts     | 24 ++++++++++++------------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 302016a07a..ecb425d545 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -31,7 +31,7 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
-export type ArgumentTypes = "string" | "number"
+export type ArgumentTypes = 'string' | 'number'
 
 export interface FunctionArgumentDefinition {
   argumentType: string,
@@ -90,11 +90,11 @@ export abstract class FunctionPlugin {
   }
 
   protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ argumentType: "number"}], fn)
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ argumentType: 'number'}], fn)
   }
 
   protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ argumentType: "string" }], fn)
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ argumentType: 'string' }], fn)
   }
 
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 21e03a3db5..c551e7ad30 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -34,38 +34,38 @@ export class TextPlugin extends FunctionPlugin {
     'REPT': {
       method: 'rept',
       parameters: [
-        { argumentType: "string" },
-        { argumentType: "number" },
+        { argumentType: 'string' },
+        { argumentType: 'number' },
       ],
     },
     'RIGHT': {
       method: 'right',
       parameters: [
-        { argumentType: "string" },
-        { argumentType: "number", defaultValue: 1 },
+        { argumentType: 'string' },
+        { argumentType: 'number', defaultValue: 1 },
       ],
     },
     'LEFT': {
       method: 'left',
       parameters: [
-        { argumentType: "string" },
-        { argumentType: "number", defaultValue: 1 },
+        { argumentType: 'string' },
+        { argumentType: 'number', defaultValue: 1 },
       ],
     },
     'SEARCH': {
       method: 'search',
       parameters: [
-        { argumentType: "string" },
-        { argumentType: "string" },
-        { argumentType: "number", defaultValue: 1 },
+        { argumentType: 'string' },
+        { argumentType: 'string' },
+        { argumentType: 'number', defaultValue: 1 },
       ],
     },
     'FIND': {
       method: 'find',
       parameters: [
-        { argumentType: "string" },
-        { argumentType: "string" },
-        { argumentType: "number", defaultValue: 1 },
+        { argumentType: 'string' },
+        { argumentType: 'string' },
+        { argumentType: 'number', defaultValue: 1 },
       ],
     }
   }

From b8c2d3f8f236b2307e2cd92e1f340fb1c4c4d334 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Tue, 21 Jul 2020 16:07:58 +0200
Subject: [PATCH 16/97] split fixed

---
 src/interpreter/plugin/TextPlugin.ts | 34 +++++++++-------------------
 1 file changed, 11 insertions(+), 23 deletions(-)

diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index c551e7ad30..09eeb375a8 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -18,6 +18,10 @@ export class TextPlugin extends FunctionPlugin {
     },
     'SPLIT': {
       method: 'split',
+      parameters: [
+        { argumentType: 'string' },
+        { argumentType: 'number' },
+      ],
     },
     'LEN': {
       method: 'len'
@@ -107,31 +111,15 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public split(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const stringArg = ast.args[0]
-    const indexArg = ast.args[1]
+    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.SPLIT.parameters, (stringToSplit: string, indexToUse: number) => {
+      const splittedString = stringToSplit.split(' ')
 
-    const stringToSplit = this.evaluateAst(stringArg, formulaAddress)
-    if (typeof stringToSplit !== 'string') {
-      return new CellError(ErrorType.VALUE)
-    }
-    const indexToUse = this.evaluateAst(indexArg, formulaAddress)
-    if (typeof indexToUse !== 'number') {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const splittedString = stringToSplit.split(' ')
-
-    if (indexToUse > splittedString.length || indexToUse < 0) {
-      return new CellError(ErrorType.VALUE)
-    }
+      if (indexToUse >= splittedString.length || indexToUse < 0) {
+        return new CellError(ErrorType.VALUE)
+      }
 
-    return splittedString[indexToUse]
+      return splittedString[indexToUse]
+    })
   }
 
   public len(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {

From 878acd5826a0eeea83d4677aa2f78b836347fee3 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Tue, 21 Jul 2020 23:30:13 +0200
Subject: [PATCH 17/97] .

---
 src/interpreter/plugin/FunctionPlugin.ts | 28 +++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index ecb425d545..7f74873369 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -157,6 +157,7 @@ export abstract class FunctionPlugin {
         return coerceScalarToString(arg)
     }
   }
+
   protected coerceArgumentsWithDefaults = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
@@ -168,6 +169,31 @@ export abstract class FunctionPlugin {
     }
 
     const coercedArguments: InternalScalarValue[] = []
+
+    for (let i = 0; i < argumentDefinitions.length; ++i) {
+      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
+      if (arg instanceof SimpleRangeValue) {
+        return new CellError(ErrorType.VALUE)
+      }
+      const coercedArg = this.coerceToType(arg, argumentDefinitions[i].argumentType as ArgumentTypes)
+      if (coercedArg instanceof CellError) {
+        return coercedArg
+      }
+      coercedArguments.push(coercedArg)
+    }
+
+    return fn(...coercedArguments)
+  }
+
+
+  protected coerceRepeatedArgumentsWithDefaults = (
+    args: Ast[],
+    formulaAddress: SimpleCellAddress,
+    argumentDefinitions: FunctionArgumentDefinition[],
+    fn: (...arg: any) => InternalScalarValue
+  ) => {
+    const coercedArguments: InternalScalarValue[] = []
+
     for (let i = 0; i < argumentDefinitions.length; ++i) {
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
       if (arg instanceof SimpleRangeValue) {
@@ -187,6 +213,6 @@ export abstract class FunctionPlugin {
     if (argAst !== undefined) {
       return this.evaluateAst(argAst, formulaAddress)
     }
-    return defaultValue || new CellError(ErrorType.NA)
+    return defaultValue ?? new CellError(ErrorType.NA)
   }
 }

From 6501069b66f688b4f4e4fa4bdbacd55d72aa93bf Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 00:25:13 +0200
Subject: [PATCH 18/97] .

---
 src/interpreter/plugin/FunctionPlugin.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 7f74873369..8ab6ead916 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -194,7 +194,7 @@ export abstract class FunctionPlugin {
   ) => {
     const coercedArguments: InternalScalarValue[] = []
 
-    for (let i = 0; i < argumentDefinitions.length; ++i) {
+    for (let i = 0; i < Math.max(argumentDefinitions.length, args.length); ++i) {
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
       if (arg instanceof SimpleRangeValue) {
         return new CellError(ErrorType.VALUE)

From 3139f737bb5c56e2cb435b3715e7b1504d6f782d Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 12:51:54 +0200
Subject: [PATCH 19/97] financial simpler

---
 src/interpreter/plugin/FinancialPlugin.ts | 196 ++++------------------
 src/interpreter/plugin/FunctionPlugin.ts  |   8 +-
 src/interpreter/plugin/TextPlugin.ts      |  12 +-
 3 files changed, 44 insertions(+), 172 deletions(-)

diff --git a/src/interpreter/plugin/FinancialPlugin.ts b/src/interpreter/plugin/FinancialPlugin.ts
index edaf460a16..e31d644d4c 100644
--- a/src/interpreter/plugin/FinancialPlugin.ts
+++ b/src/interpreter/plugin/FinancialPlugin.ts
@@ -12,190 +12,62 @@ export class FinancialPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'PMT': {
       method: 'pmt',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0 },
+        { argumentType: 'number', defaultValue: 0 },
+      ],
     },
     'IPMT': {
       method: 'ipmt',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0 },
+        { argumentType: 'number', defaultValue: 0 },
+      ],
     },
     'PPMT': {
       method: 'ppmt',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0 },
+        { argumentType: 'number', defaultValue: 0 },
+      ],
     },
     'FV': {
       method: 'fv',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0 },
+        { argumentType: 'number', defaultValue: 0 },
+      ],
     },
   }
 
-  private template5(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg1: number, arg2: number, arg3: number, arg4: number, arg5: number) => number): InternalScalarValue {
-    if (ast.args.length < 3 || ast.args.length > 5) {
-      return new CellError(ErrorType.NA)
-    }
-
-    if(ast.args[0].type === AstNodeType.EMPTY || ast.args[1].type === AstNodeType.EMPTY || ast.args[2].type === AstNodeType.EMPTY) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    let arg1 = this.evaluateAst(ast.args[0], formulaAddress)
-    if(arg1 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let arg2 = this.evaluateAst(ast.args[1], formulaAddress)
-    if(arg2 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let arg3 = this.evaluateAst(ast.args[2], formulaAddress)
-    if(arg3 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let arg4, arg5
-    if(ast.args.length < 4 || ast.args[3].type === AstNodeType.EMPTY) {
-      arg4 = 0
-    } else {
-      arg4 = this.evaluateAst(ast.args[3], formulaAddress)
-    }
-
-    if(arg4 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    if(ast.args.length < 5 || ast.args[4].type === AstNodeType.EMPTY) {
-      arg5 = 0
-    } else {
-      arg5 = this.evaluateAst(ast.args[4], formulaAddress)
-    }
-
-    if(arg5 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-
-    arg1 = this.coerceScalarToNumberOrError(arg1)
-    if(arg1 instanceof CellError) {
-      return arg1
-    }
-
-    arg2 = this.coerceScalarToNumberOrError(arg2)
-    if(arg2 instanceof CellError) {
-      return arg2
-    }
-
-    arg3 = this.coerceScalarToNumberOrError(arg3)
-    if(arg3 instanceof CellError) {
-      return arg3
-    }
-
-    arg4 = this.coerceScalarToNumberOrError(arg4)
-    if(arg4 instanceof CellError) {
-      return arg4
-    }
-
-    arg5 = this.coerceScalarToNumberOrError(arg5)
-    if(arg5 instanceof CellError) {
-      return arg5
-    }
-
-    return fn(arg1, arg2, arg3, arg4, arg5)
-  }
-
-  private template6(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg1: number, arg2: number, arg3: number, arg4: number, arg5: number, arg6: number) => number): InternalScalarValue {
-    if (ast.args.length < 4 || ast.args.length > 6) {
-      return new CellError(ErrorType.NA)
-    }
-
-    if(ast.args[0].type === AstNodeType.EMPTY || ast.args[1].type === AstNodeType.EMPTY || ast.args[2].type === AstNodeType.EMPTY || ast.args[3].type === AstNodeType.EMPTY) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    let arg1 = this.evaluateAst(ast.args[0], formulaAddress)
-    if(arg1 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let arg2 = this.evaluateAst(ast.args[1], formulaAddress)
-    if(arg2 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let arg3 = this.evaluateAst(ast.args[2], formulaAddress)
-    if(arg3 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let arg4 = this.evaluateAst(ast.args[3], formulaAddress)
-    if(arg4 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let arg5, arg6
-    if(ast.args.length < 5 || ast.args[4].type === AstNodeType.EMPTY) {
-      arg5 = 0
-    } else {
-      arg5 = this.evaluateAst(ast.args[4], formulaAddress)
-    }
-
-    if(arg5 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    if(ast.args.length < 6 || ast.args[5].type === AstNodeType.EMPTY) {
-      arg6 = 0
-    } else {
-      arg6 = this.evaluateAst(ast.args[5], formulaAddress)
-    }
-
-    if(arg6 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-
-    arg1 = this.coerceScalarToNumberOrError(arg1)
-    if(arg1 instanceof CellError) {
-      return arg1
-    }
-
-    arg2 = this.coerceScalarToNumberOrError(arg2)
-    if(arg2 instanceof CellError) {
-      return arg2
-    }
-
-    arg3 = this.coerceScalarToNumberOrError(arg3)
-    if(arg3 instanceof CellError) {
-      return arg3
-    }
-
-    arg4 = this.coerceScalarToNumberOrError(arg4)
-    if(arg4 instanceof CellError) {
-      return arg4
-    }
-
-    arg5 = this.coerceScalarToNumberOrError(arg5)
-    if(arg5 instanceof CellError) {
-      return arg5
-    }
-
-    arg6 = this.coerceScalarToNumberOrError(arg6)
-    if(arg6 instanceof CellError) {
-      return arg6
-    }
-
-    return fn(arg1, arg2, arg3, arg4, arg5, arg6)
-  }
-
   public pmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.template5(ast, formulaAddress, pmtCore)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.PMT.parameters, pmtCore)
   }
 
   public ipmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.template6(ast, formulaAddress, ipmtCore)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.IPMT.parameters, ipmtCore)
   }
 
   public ppmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.template6(ast, formulaAddress, ppmtCore)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.PPMT.parameters, ppmtCore)
   }
 
   public fv(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.template5(ast, formulaAddress, fvCore)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.FV.parameters, fvCore)
   }
 }
 
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 8ab6ead916..062d23b8c1 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -90,11 +90,11 @@ export abstract class FunctionPlugin {
   }
 
   protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ argumentType: 'number'}], fn)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, [{ argumentType: 'number'}], fn)
   }
 
   protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ argumentType: 'string' }], fn)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, [{ argumentType: 'string' }], fn)
   }
 
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
@@ -158,7 +158,7 @@ export abstract class FunctionPlugin {
     }
   }
 
-  protected coerceArgumentsWithDefaults = (
+  protected runFunctionWithDefaults = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
     argumentDefinitions: FunctionArgumentDefinition[],
@@ -186,7 +186,7 @@ export abstract class FunctionPlugin {
   }
 
 
-  protected coerceRepeatedArgumentsWithDefaults = (
+  protected runFunctionWithRepeatedArg = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
     argumentDefinitions: FunctionArgumentDefinition[],
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 09eeb375a8..d244f575e1 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -111,7 +111,7 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public split(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.SPLIT.parameters, (stringToSplit: string, indexToUse: number) => {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.SPLIT.parameters, (stringToSplit: string, indexToUse: number) => {
       const splittedString = stringToSplit.split(' ')
 
       if (indexToUse >= splittedString.length || indexToUse < 0) {
@@ -148,7 +148,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public rept(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.REPT.parameters, (text: string, count: number) => {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.REPT.parameters, (text: string, count: number) => {
       if (count < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -157,7 +157,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public right(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.RIGHT.parameters, (text: string, length: number) => {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.RIGHT.parameters, (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       } else if (length === 0) {
@@ -168,7 +168,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public left(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.LEFT.parameters, (text: string, length: number) => {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.LEFT.parameters, (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -177,7 +177,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public search(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.SEARCH.parameters, (pattern, text: string, startIndex: number) => {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.SEARCH.parameters, (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }
@@ -197,7 +197,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public find(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.FIND.parameters, (pattern, text: string, startIndex: number) => {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.FIND.parameters, (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }

From 0ff0807653afdae3e57f376341ab0866f9ee9c0d Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 14:12:17 +0200
Subject: [PATCH 20/97] repeated args

---
 src/interpreter/plugin/FunctionPlugin.ts | 22 +++++++++++++++-------
 src/interpreter/plugin/TextPlugin.ts     | 23 ++++++-----------------
 2 files changed, 21 insertions(+), 24 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 062d23b8c1..157b629002 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -185,25 +185,33 @@ export abstract class FunctionPlugin {
     return fn(...coercedArguments)
   }
 
-
   protected runFunctionWithRepeatedArg = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
     argumentDefinitions: FunctionArgumentDefinition[],
+    repeatedArgs: number,
     fn: (...arg: any) => InternalScalarValue
   ) => {
+    const scalarValues: InternalScalarValue[] = [...this.iterateOverScalarValues(args, formulaAddress)]
     const coercedArguments: InternalScalarValue[] = []
 
-    for (let i = 0; i < Math.max(argumentDefinitions.length, args.length); ++i) {
-      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
-      if (arg instanceof SimpleRangeValue) {
-        return new CellError(ErrorType.VALUE)
-      }
-      const coercedArg = this.coerceToType(arg, argumentDefinitions[i].argumentType as ArgumentTypes)
+    let j = 0
+    let i = 0
+    while(true) {
+      const arg = scalarValues[i] ?? argumentDefinitions[j].defaultValue ?? new CellError(ErrorType.NA)
+      const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
       if (coercedArg instanceof CellError) {
         return coercedArg
       }
       coercedArguments.push(coercedArg)
+      j++
+      i++
+      if(i >= scalarValues.length && j === argumentDefinitions.length) {
+        break
+      }
+      if(j===argumentDefinitions.length) {
+        j -= repeatedArgs
+      }
     }
 
     return fn(...coercedArguments)
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index d244f575e1..1f85b6c1b1 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -15,6 +15,9 @@ export class TextPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CONCATENATE': {
       method: 'concatenate',
+      parameters: [
+        { argumentType: 'string'}
+      ]
     },
     'SPLIT': {
       method: 'split',
@@ -83,23 +86,9 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public concatenate(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length == 0) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    let result = ''
-    for (const value of this.iterateOverScalarValues(ast.args, formulaAddress)) {
-      const coercedValue = coerceScalarToString(value)
-      if (coercedValue instanceof CellError) {
-        return value
-      } else {
-        result = result.concat(coercedValue)
-      }
-    }
-    return result
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, TextPlugin.implementedFunctions.CONCATENATE.parameters, 1, (...args) => {
+      return ''.concat(...args)
+    })
   }
 
   /**

From fb9e6153428b37f013f4a1f7bae0cc5f922b99fa Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 14:35:15 +0200
Subject: [PATCH 21/97] translations

---
 src/i18n/languages/csCZ.ts | 4 ++++
 src/i18n/languages/daDK.ts | 4 ++++
 src/i18n/languages/deDE.ts | 6 +++++-
 src/i18n/languages/enGB.ts | 4 ++++
 src/i18n/languages/esES.ts | 4 ++++
 src/i18n/languages/fiFI.ts | 4 ++++
 src/i18n/languages/frFR.ts | 4 ++++
 src/i18n/languages/huHU.ts | 4 ++++
 src/i18n/languages/itIT.ts | 4 ++++
 src/i18n/languages/nbNO.ts | 4 ++++
 src/i18n/languages/nlNL.ts | 4 ++++
 src/i18n/languages/plPL.ts | 4 ++++
 src/i18n/languages/ptPT.ts | 4 ++++
 src/i18n/languages/ruRU.ts | 4 ++++
 src/i18n/languages/svSE.ts | 4 ++++
 src/i18n/languages/trTR.ts | 4 ++++
 16 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 5a9ea44498..fbf500a5c0 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'NEPRAVDA',
     FIND: 'NAJÍT',
+    FV: 'BUDHODNOTA',
     IF: 'KDYŽ',
     IFERROR: 'IFERROR',
     IFNA: 'IFNA',
     INDEX: 'INDEX',
     INT: 'CELÁ.ČÁST',
+    IPMT: 'PLATBA.ÚROK',
     ISBLANK: 'JE.PRÁZDNÉ',
     ISERROR: 'JE.CHYBHODN',
     ISEVEN: 'ISEVEN',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'POSUN',
     OR: 'NEBO',
     PI: 'PI',
+    PMT: 'PLATBA',
     POWER: 'POWER',
+    PPMT: 'PLATBA.ZÁKLAD',
     PROPER: 'VELKÁ2',
     RADIANS: 'RADIANS',
     RAND: 'NÁHČÍSLO',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 42533a25ca..f433a47d37 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EKSP',
     FALSE: 'FALSE',
     FIND: 'FIND',
+    FV: 'FV',
     IF: 'HVIS',
     IFERROR: 'HVIS.FEJL',
     IFNA: 'HVISIT',
     INDEX: 'INDEKS',
     INT: 'HELTAL',
+    IPMT: 'R.YDELSE',
     ISBLANK: 'ER.TOM',
     ISERROR: 'ER.FEJL',
     ISEVEN: 'ER.LIGE',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'FORSKYDNING',
     OR: 'ELLER',
     PI: 'PI',
+    PMT: 'YDELSE',
     POWER: 'POTENS',
+    PPMT: 'H.YDELSE',
     PROPER: 'STORT.FORBOGSTAV',
     RADIANS: 'RADIANER',
     RAND: 'SLUMP',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 6f3228547b..0ad4eb8aca 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'FALSCH',
     FIND: 'FINDEN',
+    FV: 'ZW',
     IF: 'WENN',
     IFERROR: 'WENNFEHLER',
     IFNA: 'WENNNV',
     INDEX: 'INDEX',
     INT: 'GANZZAHL',
+    IPMT: 'ZINSZ',
     ISBLANK: 'ISTLEER',
     ISERROR: 'ISTFEHLER',
     ISEVEN: 'ISTGERADE',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'BEREICH.VERSCHIEBEN',
     OR: 'ODER',
     PI: 'PI',
+    PMT: 'RMZ',
     POWER: 'POTENZ',
+    PPMT: 'KAPZ',
     PROPER: 'GROSS2',
     RADIANS: 'BOGENMASS',
     RAND: 'ZUFALLSZAHL',
@@ -139,4 +143,4 @@ const dictionary: RawTranslationPackage = {
   },
 }
 
-export default dictionary
\ No newline at end of file
+export default dictionary
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 6b259115c3..1651926176 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'FALSE',
     FIND: 'FIND',
+    FV: 'FV',
     IF: 'IF',
     IFERROR: 'IFERROR',
     IFNA: 'IFNA',
     INDEX: 'INDEX',
     INT: 'INT',
+    IPMT: 'IPMT',
     ISBLANK: 'ISBLANK',
     ISERROR: 'ISERROR',
     ISEVEN: 'ISEVEN',
@@ -103,6 +105,8 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'OFFSET',
     OR: 'OR',
     PI: 'PI',
+    PMT: 'PMT',
+    PPMT: 'PPMT',
     POWER: 'POWER',
     PROPER: 'PROPER',
     RADIANS: 'RADIANS',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 85c9b3fc88..7224293181 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -69,11 +69,13 @@ export const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'FALSO',
     FIND: 'ENCONTRAR',
+    FV: 'VF',
     IF: 'SI',
     IFERROR: 'SI.ERROR',
     IFNA: 'IFNA',
     INDEX: 'INDICE',
     INT: 'ENTERO',
+    IPMT: 'PAGOINT',
     ISBLANK: 'ESBLANCO',
     ISERROR: 'ESERROR',
     ISEVEN: 'ES.PAR',
@@ -103,7 +105,9 @@ export const dictionary: RawTranslationPackage = {
     OFFSET: 'DESREF',
     OR: 'O',
     PI: 'PI',
+    PMT: 'PAGO',
     POWER: 'POTENCIA',
+    PPMT: 'PAGOPRIN',
     PROPER: 'NOMPROPIO',
     RADIANS: 'RADIANES',
     RAND: 'ALEATORIO',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 179f52870a..1e1374fa08 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EKSPONENTTI',
     FALSE: 'EPÄTOSI',
     FIND: 'ETSI',
+    FV: 'TULEVA.ARVO',
     IF: 'JOS',
     IFERROR: 'JOSVIRHE',
     IFNA: 'JOSPUUTTUU',
     INDEX: 'INDEKSI',
     INT: 'KOKONAISLUKU',
+    IPMT: 'IPMT',
     ISBLANK: 'ONTYHJÄ',
     ISERROR: 'ONVIRHE',
     ISEVEN: 'ONPARILLINEN',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'SIIRTYMÄ',
     OR: 'TAI',
     PI: 'PII',
+    PMT: 'MAKSU',
     POWER: 'POTENSSI',
+    PPMT: 'PPMT',
     PROPER: 'ERISNIMI',
     RADIANS: 'RADIAANIT',
     RAND: 'SATUNNAISLUKU',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 0c0cdd76f1..bd8a20cf41 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'FAUX',
     FIND: 'TROUVE',
+    FV: 'VC',
     IF: 'SI',
     IFERROR: 'SIERREUR',
     IFNA: 'SI.NON.DISP',
     INDEX: 'INDEX',
     INT: 'ENT',
+    IPMT: 'INTPER',
     ISBLANK: 'ESTVIDE',
     ISERROR: 'ESTERREUR',
     ISEVEN: 'EST.PAIR',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'DECALER',
     OR: 'OU',
     PI: 'PI',
+    PMT: 'VPM',
     POWER: 'PUISSANCE',
+    PPMT: 'PRINCPER',
     PROPER: 'NOMPROPRE',
     RADIANS: 'RADIANS',
     RAND: 'ALEA',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index e6e256eec8..9865ce32e4 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'KITEVŐ',
     FALSE: 'HAMIS',
     FIND: 'SZÖVEG.TALÁL',
+    FV: 'JBÉ',
     IF: 'HA',
     IFERROR: 'HAHIBA',
     IFNA: 'HAHIÁNYZIK',
     INDEX: 'INDEX',
     INT: 'INT',
+    IPMT: 'RRÉSZLET',
     ISBLANK: 'ÜRES',
     ISERROR: 'HIBÁS',
     ISEVEN: 'PÁROSE',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'ELTOLÁS',
     OR: 'VAGY',
     PI: 'PI',
+    PMT: 'RÉSZLET',
     POWER: 'HATVÁNY',
+    PPMT: 'PRÉSZLET',
     PROPER: 'TNÉV',
     RADIANS: 'RADIÁN',
     RAND: 'VÉL',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index ab30e4a621..98d7c71c14 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'FALSO',
     FIND: 'TROVA',
+    FV: 'VAL.FUT',
     IF: 'SE',
     IFERROR: 'SE.ERRORE',
     IFNA: 'SE.NON.DISP.',
     INDEX: 'INDICE',
     INT: 'INT',
+    IPMT: 'INTERESSI',
     ISBLANK: 'VAL.VUOTO',
     ISERROR: 'VAL.ERRORE',
     ISEVEN: 'VAL.PARI',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'SCARTO',
     OR: 'O',
     PI: 'PI.GRECO',
+    PMT: 'RATA',
     POWER: 'POTENZA',
+    PPMT: 'P.RATA',
     PROPER: 'MAIUSC.INIZ',
     RADIANS: 'RADIANTI',
     RAND: 'CASUALE',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index dad06fd788..f3f0253234 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EKSP',
     FALSE: 'USANN',
     FIND: 'FINN',
+    FV: 'SLUTTVERDI',
     IF: 'HVIS',
     IFERROR: 'HVISFEIL',
     IFNA: 'HVIS.IT',
     INDEX: 'INDEKS',
     INT: 'HELTALL',
+    IPMT: 'RAVDRAG',
     ISBLANK: 'ERTOM',
     ISERROR: 'ERFEIL',
     ISEVEN: 'ERPARTALL',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'FORSKYVNING',
     OR: 'ELLER',
     PI: 'PI',
+    PMT: 'AVDRAG',
     POWER: 'OPPHØYD.I',
+    PPMT: 'AMORT',
     PROPER: 'STOR.FORBOKSTAV',
     RADIANS: 'RADIANER',
     RAND: 'TILFELDIG',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index e7539646d1..b564591d23 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'ONWAAR',
     FIND: 'VIND.ALLES',
+    FV: 'TW',
     IF: 'ALS',
     IFERROR: 'ALS.FOUT',
     IFNA: 'ALS.NB',
     INDEX: 'INDEX',
     INT: 'INTEGER',
+    IPMT: 'IBET',
     ISBLANK: 'ISLEEG',
     ISERROR: 'ISFOUT',
     ISEVEN: 'IS.EVEN',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'VERSCHUIVING',
     OR: 'OF',
     PI: 'PI',
+    PMT: 'BET',
     POWER: 'MACHT',
+    PPMT: 'PBET',
     PROPER: 'BEGINLETTERS',
     RADIANS: 'RADIALEN',
     RAND: 'ASELECT',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index 458650fdff..a20f60c698 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'FAŁSZ',
     FIND: 'ZNAJDŹ',
+    FV: 'FV',
     IF: 'JEŻELI',
     IFERROR: 'JEŻELI.BŁĄD',
     IFNA: 'JEŻELI.ND',
     INDEX: 'INDEKS',
     INT: 'ZAOKR.DO.CAŁK',
+    IPMT: 'IPMT',
     ISBLANK: 'CZY.PUSTA',
     ISERROR: 'CZY.BŁĄD',
     ISEVEN: 'CZY.PARZYSTE',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'PRZESUNIĘCIE',
     OR: 'LUB',
     PI: 'PI',
+    PMT: 'PMT',
     POWER: 'POTĘGA',
+    PPMT: 'PPMT',
     PROPER: 'Z.WIELKIEJ.LITERY',
     RADIANS: 'RADIANY',
     RAND: 'LOSUJ',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 66ec685dcf..04d7b85581 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'FALSO',
     FIND: 'PROCURAR',
+    FV: 'VF',
     IF: 'SE',
     IFERROR: 'SEERRO',
     IFNA: 'SENA',
     INDEX: 'ÍNDICE',
     INT: 'INT',
+    IPMT: 'IPGTO',
     ISBLANK: 'ÉCÉL.VAZIA',
     ISERROR: 'ÉERROS',
     ISEVEN: 'ÉPAR',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'DESLOC',
     OR: 'OU',
     PI: 'PI',
+    PMT: 'PGTO',
     POWER: 'POTÊNCIA',
+    PPMT: 'PPGTO',
     PROPER: 'PRI.MAIÚSCULA',
     RADIANS: 'RADIANOS',
     RAND: 'ALEATÓRIO',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index f62b9058bb..b87adcb7b8 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'ЛОЖЬ',
     FIND: 'НАЙТИ',
+    FV: 'БС',
     IF: 'ЕСЛИ',
     IFERROR: 'ЕСЛИОШИБКА',
     IFNA: 'ЕСНД',
     INDEX: 'ИНДЕКС',
     INT: 'ЦЕЛОЕ',
+    IPMT: 'ПРПЛТ',
     ISBLANK: 'ЕПУСТО',
     ISERROR: 'ЕОШИБКА',
     ISEVEN: 'ЕЧЁТН',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'СМЕЩ',
     OR: 'ИЛИ',
     PI: 'ПИ',
+    PMT: 'ПЛТ',
     POWER: 'СТЕПЕНЬ',
+    PPMT: 'ОСПЛТ',
     PROPER: 'ПРОПНАЧ',
     RADIANS: 'РАДИАНЫ',
     RAND: 'СЛЧИС',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 52865fcd76..214af6eb33 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'EXP',
     FALSE: 'FALSKT',
     FIND: 'HITTA',
+    FV: 'SLUTVÄRDE',
     IF: 'OM',
     IFERROR: 'OMFEL',
     IFNA: 'IFNA',
     INDEX: 'INDEX',
     INT: 'HELTAL',
+    IPMT: 'RBETALNING',
     ISBLANK: 'ÄRTOM',
     ISERROR: 'ÄRFEL',
     ISEVEN: 'ÄRJÄMN',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'FÖRSKJUTNING',
     OR: 'ELLER',
     PI: 'PI',
+    PMT: 'BETALNING',
     POWER: 'UPPHÖJT.TILL',
+    PPMT: 'AMORT',
     PROPER: 'INITIAL',
     RADIANS: 'RADIANER',
     RAND: 'SLUMP',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 7fa5ad112e..7d07640413 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -69,11 +69,13 @@ const dictionary: RawTranslationPackage = {
     EXP: 'ÜS',
     FALSE: 'YANLIŞ',
     FIND: 'BUL',
+    FV: 'GD',
     IF: 'EĞER',
     IFERROR: 'EĞERHATA',
     IFNA: 'EĞERYOKSA',
     INDEX: 'İNDİS',
     INT: 'TAMSAYI',
+    IPMT: 'FAİZTUTARI',
     ISBLANK: 'EBOŞSA',
     ISERROR: 'EHATALIYSA',
     ISEVEN: 'ÇİFTMİ',
@@ -103,7 +105,9 @@ const dictionary: RawTranslationPackage = {
     OFFSET: 'KAYDIR',
     OR: 'VEYA',
     PI: 'Pİ',
+    PMT: 'DEVRESEL_ÖDEME',
     POWER: 'KUVVET',
+    PPMT: 'ANA_PARA_ÖDEMESİ',
     PROPER: 'YAZIM.DÜZENİ',
     RADIANS: 'RADYAN',
     RAND: 'S_SAYI_ÜRET',

From 2692dbbb40abb37459b45519a6c319f6791b5039 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 14:54:12 +0200
Subject: [PATCH 22/97] changelog

---
 CHANGELOG.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index daab4c0d23..cededbcc3d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
-- Added helper functions for keeping track of cell/range dependencies: getCellPrecedents and getCellDependents. (#441)
+- 11 text functions CONCATENATE, SPLIT, LEN, TRIM, PROPER, CLEAN, REPT, RIGHT, LEFT, SEARCH, FIND.
+- helper methods for keeping track of cell/range dependencies: getCellPrecedents and getCellDependents. (#441)
 - 4 financial functions FV, PMT, PPMT, IPMT.
 
 ## [0.1.3] - 2020-07-21

From 28bf8a8a3ab33d85ea305c6fdafb0a13d6b4ca7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Wed, 22 Jul 2020 14:56:54 +0200
Subject: [PATCH 23/97] Update built-in-functions.md

reorder
---
 docs/guide/built-in-functions.md | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index 3db556a714..29d18ef9d6 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -75,7 +75,6 @@ lets you design your own [custom functions](custom-functions).
 | BITOR | Engineering | Returns a bitwise logical "or" of the parameters. | BITOR(Number1; Number2) |
 | BITRSHIFT | Engineering | Shifts a number right by n bits. | BITRSHIFT(Number; Shift) |
 | BITXOR | Engineering | Returns a bitwise logical "exclusive or" of the parameters. | BITXOR(Number1; Number2) |
-| CHOOSE | Lookup and reference | Uses an index to return a value from a list of up to 30 values.| CHOOSE(Index; Value1; ...; Value30) |
 | DEC2BIN | Engineering | Returns the binary number for the decimal number entered between –512 and 511. | DEC2BIN(Number; Places) |
 | DEC2HEX | Engineering | Returns the hexadecimal number for the decimal number entered. | DEC2HEX(Number; Places) |
 | DEC2OCT | Engineering | Returns the octal number for the decimal number entered. | DEC2OCT(Number; Places) |
@@ -104,12 +103,12 @@ lets you design your own [custom functions](custom-functions).
 | OR | Logical | Returns TRUE if at least one argument is TRUE. | OR(Logicalvalue1; Logicalvalue2 ...Logicalvalue30) |
 | TRUE | Logical | The logical value is set to TRUE. | TRUE() |
 | XOR | Logical | Returns true if an odd number of arguments evaluates to TRUE. | XOR(Logicalvalue1; Logicalvalue2 ...Logicalvalue30) |
+| CHOOSE | Lookup and reference | Uses an index to return a value from a list of up to 30 values.| CHOOSE(Index; Value1; ...; Value30) |
 | COLUMNS | Lookup and reference | Returns the number of columns in the given reference. | COLUMNS(Array) |
 | OFFSET | Lookup and reference | Returns the value of a cell offset by a certain number of rows and columns from a given reference point. | OFFSET(Reference; Rows; Columns; Height; Width) |
 | ROWS | Lookup and reference | Returns the number of rows in the given reference. | ROWS(Array) |
 | INDEX | Lookup and reference | Returns the content of a cell, specified by row and column number, or an optional range name. | INDEX(Reference; Row; Column; Range) |
 | MATCH | Lookup and reference | Returns the relative position of an item in an array that matches a specified value. | MATCH(Searchcriterion; Lookuparray; Type) |
-| TRANSPOSE | Matrix functions | Transposes the rows and columns of an array. | TRANSPOSE(Array) |
 | VLOOKUP | Lookup and reference | Searches vertically with reference to adjacent cells to the right. | VLOOKUP(Search_Criterion; Array; Index; Sort_Order) |
 | ABS | Math and trigonometry | Returns the absolute value of a number. | ABS(Number) |
 | ACOS | Math and trigonometry | Returns the inverse trigonometric cosine of a number. | ACOS(Number) |
@@ -130,9 +129,6 @@ lets you design your own [custom functions](custom-functions).
 | LN | Math and trigonometry | Returns the natural logarithm based on the constant e of a number. | LN(Number) |
 | LOG | Math and trigonometry | Returns the logarithm of a number to the specified base. | LOG(Number; Base) |
 | LOG10 | Math and trigonometry | Returns the base-10 logarithm of a number. | LOG10(Number) |
-| MMULT | Matrix functions | Calculates the array product of two arrays. | MMULT(Array; Array) |
-| MEDIANPOOL | Matrix functions | Calculates a smaller range which is a median of a Window_size, in a given Range, for every Stride element. | MEDIANPOOL(Range, Window_size, Stride) |
-| MAXPOOL | Matrix functions | Calculates a smaller range which is a maximum of a Window_size, in a given Range, for every Stride element. | MAXPOOL(Range, Window_size, Stride) |
 | MOD | Math and trigonometry | Returns the remainder when one integer is divided by another. | MOD(Dividend; Divisor) |
 | ODD | Math and trigonometry | Rounds a positive number up to the nearest odd integer and a negative number down to the nearest odd integer. | ODD(Number) |
 | PI | Math and trigonometry | Returns 3.14159265358979, the value of the mathematical constant PI to 14 decimal places. | PI() |
@@ -151,6 +147,10 @@ lets you design your own [custom functions](custom-functions).
 | SUMSQ | Math and trigonometry | Returns the sum of the squares of the arguments | SUMSQ(Number1; Number2; ...; Number30) |
 | TAN | Math and trigonometry | Returns the tangent of the given angle (in radians). | TAN(Number) |
 | TRUNC | Math and trigonometry | Truncates a number by removing decimal places. | TRUNC(Number; Count) |
+| MMULT | Matrix functions | Calculates the array product of two arrays. | MMULT(Array; Array) |
+| MEDIANPOOL | Matrix functions | Calculates a smaller range which is a median of a Window_size, in a given Range, for every Stride element. | MEDIANPOOL(Range, Window_size, Stride) |
+| MAXPOOL | Matrix functions | Calculates a smaller range which is a maximum of a Window_size, in a given Range, for every Stride element. | MAXPOOL(Range, Window_size, Stride) |
+| TRANSPOSE | Matrix functions | Transposes the rows and columns of an array. | TRANSPOSE(Array) |
 | AVERAGE | Statistical | Returns the average of the arguments. | AVERAGE(Number1; Number2; ...Number30) |
 | AVERAGEA | Statistical | Returns the average of the arguments. | AVERAGEA(Value1; Value2; ... Value30) |
 | AVERAGEIF | Statistical | Returns the arithmetic mean of all cells in a range that satisfy a given condition. | AVERAGEIF(Range; Criterion [; Average_Range ]) |

From db5aa53c5dbd10b396da3ac3af3fde767c92b847 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 14:57:58 +0200
Subject: [PATCH 24/97] .

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c79a1ab178..34b0eb47c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
-- 11 text functions CONCATENATE, SPLIT, LEN, TRIM, PROPER, CLEAN, REPT, RIGHT, LEFT, SEARCH, FIND.
+- 9 text functions LEN, TRIM, PROPER, CLEAN, REPT, RIGHT, LEFT, SEARCH, FIND.
 - helper methods for keeping track of cell/range dependencies: getCellPrecedents and getCellDependents. (#441)
 - 4 financial functions FV, PMT, PPMT, IPMT.
 

From ea61e03aca0679e0ebba083cf27341ebad6dfc65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Wed, 22 Jul 2020 15:16:01 +0200
Subject: [PATCH 25/97] Update built-in-functions.md

---
 docs/guide/built-in-functions.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index 29d18ef9d6..21ea2c3e63 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -170,3 +170,12 @@ lets you design your own [custom functions](custom-functions).
 | CONCATENATE | Text | Combines several text strings into one string. | CONCATENATE("Text1"; ...; "Text30") |
 | SPLIT | Text | Divides text around a specified character or string, and puts each fragment into a separate cell in the row. | SPLIT(Text, Delimiter, [Split_by_each], [Remove_empty_text]) |
 | TEXT | Text | Converts a number into text according to a given format. | TEXT(Number; Format) |
+| LEN | Text | Returns length of a given text. | LEN("Text") | 
+| TRIM | Text | Strips extra spaces from text. | TRIM("Text") |
+| PROPER | Text | Capitalizes words given text string. | PROPER("Text") |
+| CLEAN | Text | Returns text that has been "cleaned" of line breaks and other non-printable characters. | CLEAN("Text") |
+| REPT | Text | Repeats text a given number of times. | REPT("Text"; Number) |
+| RIGHT | Text | Extracts a given number of characters from the right side of a text string. | RIGHT("Text"; Number) |
+| LEFT | Text | Extracts a given number of characters from the left side of a text string. | LEFT("Text"; Number) |
+| SEARCH | Text | Returns the location of one text string inside another. (Allows the use of wildcards.) | SEARCH( "Text1"; "Text2"[; Number]) |
+| FIND | Text | Returns the location of one text string inside another. | FIND( "Text1"; "Text2"[; Number]) |

From 44a896be3c4812d3b32a40f53e074289cb0848cd Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 15:29:21 +0200
Subject: [PATCH 26/97] trigonometry

---
 src/interpreter/plugin/TrigonometryPlugin.ts | 45 ++++----------------
 1 file changed, 9 insertions(+), 36 deletions(-)

diff --git a/src/interpreter/plugin/TrigonometryPlugin.ts b/src/interpreter/plugin/TrigonometryPlugin.ts
index 95e33228a0..99158a4efd 100644
--- a/src/interpreter/plugin/TrigonometryPlugin.ts
+++ b/src/interpreter/plugin/TrigonometryPlugin.ts
@@ -34,6 +34,10 @@ export class TrigonometryPlugin extends FunctionPlugin {
     },
     'ATAN2': {
       method: 'atan2',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+      ],
     },
     'COT': {
       method: 'ctg',
@@ -69,54 +73,23 @@ export class TrigonometryPlugin extends FunctionPlugin {
   }
 
   public cos(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedArg) => {
-      return Math.cos(coercedArg)
-    })
+    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, Math.cos)
   }
 
   public sin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedArg) => {
-      return Math.sin(coercedArg)
-    })
+    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, Math.sin)
   }
 
   public tan(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedArg) => {
-      return Math.tan(coercedArg)
-    })
+    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, Math.tan)
   }
 
   public atan(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedArg) => {
-      return Math.atan(coercedArg)
-    })
+    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, Math.atan)
   }
 
   public atan2(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const arg1 = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg1 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const arg2 = this.evaluateAst(ast.args[1], formulaAddress)
-    if (arg2 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const coercedArg1 = this.coerceScalarToNumberOrError(arg1)
-    if (coercedArg1 instanceof CellError) {
-      return coercedArg1
-    }
-    const coercedArg2 = this.coerceScalarToNumberOrError(arg2)
-    if (coercedArg2 instanceof CellError) {
-      return coercedArg2
-    }
-    return Math.atan2(coercedArg1, coercedArg2)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ATAN2.parameters, Math.atan2)
   }
 
   public ctg(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {

From 4eb442cfbf72b7a98de095647b201ed0c2efc237 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 16:01:32 +0200
Subject: [PATCH 27/97] .

---
 src/interpreter/plugin/FunctionPlugin.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 157b629002..8bc66eb3fe 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -9,7 +9,7 @@ import {ColumnSearchStrategy} from '../../ColumnSearch/ColumnSearchStrategy'
 import {Config} from '../../Config'
 import {DependencyGraph} from '../../DependencyGraph'
 import {Ast, AstNodeType, ProcedureAst} from '../../parser'
-import {coerceScalarToString} from '../ArithmeticHelper'
+import {coerceScalarToBoolean, coerceScalarToString} from '../ArithmeticHelper'
 import {Interpreter} from '../Interpreter'
 import {InterpreterValue, SimpleRangeValue} from '../InterpreterValue'
 import {Maybe} from '../../Maybe'
@@ -31,7 +31,7 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
-export type ArgumentTypes = 'string' | 'number'
+export type ArgumentTypes = 'string' | 'number' | 'boolean'
 
 export interface FunctionArgumentDefinition {
   argumentType: string,
@@ -155,6 +155,8 @@ export abstract class FunctionPlugin {
         return this.coerceScalarToNumberOrError(arg)
       case 'string':
         return coerceScalarToString(arg)
+      case 'boolean':
+        return coerceScalarToBoolean(arg)
     }
   }
 

From 444f1de82a3dbe920e5178db9e0607b4d31d2c3b Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 22 Jul 2020 23:56:42 +0200
Subject: [PATCH 28/97] booleans

---
 src/interpreter/ArithmeticHelper.ts      |  4 +-
 src/interpreter/plugin/BooleanPlugin.ts  | 79 +++++++++---------------
 src/interpreter/plugin/FunctionPlugin.ts |  6 +-
 test/interpreter/coercions.spec.ts       |  8 +--
 4 files changed, 37 insertions(+), 60 deletions(-)

diff --git a/src/interpreter/ArithmeticHelper.ts b/src/interpreter/ArithmeticHelper.ts
index ad26ce40ab..970ad07801 100644
--- a/src/interpreter/ArithmeticHelper.ts
+++ b/src/interpreter/ArithmeticHelper.ts
@@ -289,7 +289,7 @@ export function coerceEmptyToValue(arg: InternalNoErrorCellValue): InternalNoErr
  *
  * @param arg
  */
-export function coerceScalarToBoolean(arg: InternalScalarValue): boolean | CellError | null {
+export function coerceScalarToBoolean(arg: InternalScalarValue): boolean | CellError | undefined {
   if (arg instanceof SimpleRangeValue) {
     return new CellError(ErrorType.VALUE)
   } else if (arg instanceof CellError || typeof arg === 'boolean') {
@@ -307,7 +307,7 @@ export function coerceScalarToBoolean(arg: InternalScalarValue): boolean | CellE
     } else if (argUppered === '') {
       return false
     } else {
-      return null
+      return undefined
     }
   }
 }
diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index a487d31416..830ca02414 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -4,6 +4,7 @@
  */
 
 import {CellError, ErrorType, InternalNoErrorCellValue, InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {Maybe} from '../../Maybe'
 import {AstNodeType, ProcedureAst} from '../../parser'
 import {coerceScalarToBoolean} from '../ArithmeticHelper'
 import {InterpreterValue, SimpleRangeValue} from '../InterpreterValue'
@@ -15,7 +16,8 @@ import {FunctionPlugin} from './FunctionPlugin'
 export class BooleanPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'TRUE': {
-      method: 'literalTrue'
+      method: 'literalTrue',
+      parameters: [],
     },
     'FALSE': {
       method: 'literalFalse'
@@ -24,10 +26,16 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'conditionalIf'
     },
     'AND': {
-      method: 'and'
+      method: 'and',
+      parameters: [
+        { argumentType: 'boolean' },
+      ],
     },
     'OR': {
-      method: 'or'
+      method: 'or',
+      parameters: [
+        { argumentType: 'boolean' },
+      ],
     },
     'XOR': {
       method: 'xor'
@@ -57,13 +65,8 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param ast
    * @param formulaAddress
    */
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public literalTrue(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length > 0) {
-      return new CellError(ErrorType.NA)
-    } else {
-      return true
-    }
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.TRUE.parameters, () => true)
   }
 
   /**
@@ -127,29 +130,15 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public and(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    let result: InternalScalarValue = true
-    let anyReasonableValue = false
-    for (const scalarValue of this.iterateOverScalarValues(ast.args, formulaAddress)) {
-      const coercedValue = coerceScalarToBoolean(scalarValue)
-      if (coercedValue instanceof CellError) {
-        return coercedValue
-      } else if (coercedValue !== null) {
-        result = result && coercedValue
-        anyReasonableValue = true
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND.parameters, 1, (...args) => {
+      if(args.some((arg:Maybe<InternalScalarValue>) => arg===false)) {
+        return false
+      } else if(args.some((arg:Maybe<InternalScalarValue>) => arg!==undefined)) {
+        return true
+      } else {
+        return new CellError(ErrorType.VALUE)
       }
-    }
-    if (anyReasonableValue) {
-      return result
-    } else {
-      return new CellError(ErrorType.VALUE)
-    }
+    })
   }
 
   /**
@@ -161,27 +150,15 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public or(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    let result: InternalScalarValue | null = null
-    for (const scalarValue of this.iterateOverScalarValues(ast.args, formulaAddress)) {
-      const coercedValue = coerceScalarToBoolean(scalarValue)
-      if (coercedValue instanceof CellError) {
-        return coercedValue
-      } else if (coercedValue !== null) {
-        result = result || coercedValue
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR.parameters, 1, (...args) => {
+      if(args.some((arg:Maybe<InternalScalarValue>) => arg===true)) {
+        return true
+      } else if(args.some((arg:Maybe<InternalScalarValue>) => arg!==undefined)) {
+        return false
+      } else {
+        return new CellError(ErrorType.VALUE)
       }
-    }
-    if (result === null) {
-      return new CellError(ErrorType.VALUE)
-    } else {
-      return result
-    }
+    })
   }
 
   public not(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 8bc66eb3fe..3f6651274f 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -149,7 +149,7 @@ export abstract class FunctionPlugin {
 
   public coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
-  public coerceToType(arg: InternalScalarValue, coercedType: ArgumentTypes): InternalScalarValue {
+  public coerceToType(arg: InternalScalarValue, coercedType: ArgumentTypes): Maybe<InternalScalarValue> {
     switch(coercedType) {
       case 'number':
         return this.coerceScalarToNumberOrError(arg)
@@ -170,7 +170,7 @@ export abstract class FunctionPlugin {
       return new CellError(ErrorType.NA)
     }
 
-    const coercedArguments: InternalScalarValue[] = []
+    const coercedArguments: Maybe<InternalScalarValue>[] = []
 
     for (let i = 0; i < argumentDefinitions.length; ++i) {
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
@@ -195,7 +195,7 @@ export abstract class FunctionPlugin {
     fn: (...arg: any) => InternalScalarValue
   ) => {
     const scalarValues: InternalScalarValue[] = [...this.iterateOverScalarValues(args, formulaAddress)]
-    const coercedArguments: InternalScalarValue[] = []
+    const coercedArguments: Maybe<InternalScalarValue>[] = []
 
     let j = 0
     let i = 0
diff --git a/test/interpreter/coercions.spec.ts b/test/interpreter/coercions.spec.ts
index 88326b49d3..1d391b79df 100644
--- a/test/interpreter/coercions.spec.ts
+++ b/test/interpreter/coercions.spec.ts
@@ -61,10 +61,10 @@ describe('#coerceScalarToBoolean', () => {
     expect(coerceScalarToBoolean('FALSE')).toBe(false)
     expect(coerceScalarToBoolean('true')).toBe(true)
     expect(coerceScalarToBoolean('TRUE')).toBe(true)
-    expect(coerceScalarToBoolean(' ')).toBe(null)
-    expect(coerceScalarToBoolean(' true')).toBe(null)
-    expect(coerceScalarToBoolean('true ')).toBe(null)
-    expect(coerceScalarToBoolean('prawda')).toBe(null)
+    expect(coerceScalarToBoolean(' ')).toBe(undefined)
+    expect(coerceScalarToBoolean(' true')).toBe(undefined)
+    expect(coerceScalarToBoolean('true ')).toBe(undefined)
+    expect(coerceScalarToBoolean('prawda')).toBe(undefined)
     expect(coerceScalarToBoolean('')).toBe(false)
 
     expect(coerceScalarToBoolean(EmptyValue)).toBe(false)

From a1a0066ea7bbad23fb1bd796985e3b29f1beda76 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 01:23:51 +0200
Subject: [PATCH 29/97] boolean functions

---
 src/interpreter/plugin/BooleanPlugin.ts  | 140 +++++++++--------------
 src/interpreter/plugin/FunctionPlugin.ts |  10 +-
 test/interpreter/function-if.spec.ts     |   6 +
 3 files changed, 65 insertions(+), 91 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index 830ca02414..ff007cc8ba 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -20,10 +20,16 @@ export class BooleanPlugin extends FunctionPlugin {
       parameters: [],
     },
     'FALSE': {
-      method: 'literalFalse'
+      method: 'literalFalse',
+      parameters: [],
     },
     'IF': {
-      method: 'conditionalIf'
+      method: 'conditionalIf',
+      parameters: [
+        { argumentType: 'boolean' },
+        { argumentType: 'scalar' },
+        { argumentType: 'scalar', defaultValue: false },
+      ],
     },
     'AND': {
       method: 'and',
@@ -41,16 +47,27 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'xor'
     },
     'NOT': {
-      method: 'not'
+      method: 'not',
+      parameters: [
+        { argumentType: 'boolean' },
+      ],
     },
     'SWITCH': {
       method: 'switch'
     },
     'IFERROR': {
-      method: 'iferror'
+      method: 'iferror',
+      parameters: [
+        { argumentType: 'scalar' },
+        { argumentType: 'scalar' },
+      ],
     },
     'IFNA': {
-      method: 'ifna'
+      method: 'ifna',
+      parameters: [
+        { argumentType: 'scalar' },
+        { argumentType: 'scalar' },
+      ],
     },
     'CHOOSE': {
       method: 'choose'
@@ -77,13 +94,8 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param ast
    * @param formulaAddress
    */
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public literalFalse(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length > 0) {
-      return new CellError(ErrorType.NA)
-    } else {
-      return false
-    }
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.FALSE.parameters, () => false)
   }
 
   /**
@@ -95,30 +107,13 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public conditionalIf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InterpreterValue {
-    if (ast.args.length > 3 || ast.args.length < 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const conditionValue = this.evaluateAst(ast.args[0], formulaAddress)
-    if (conditionValue instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const condition = coerceScalarToBoolean(conditionValue)
-    if (condition === true) {
-      return this.evaluateAst(ast.args[1], formulaAddress)
-    } else if (condition === false) {
-      if (ast.args[2] !== undefined) {
-        return this.evaluateAst(ast.args[2], formulaAddress)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IF.parameters, (condition, arg2, arg3) => {
+      if(condition===undefined) {
+        return new CellError(ErrorType.VALUE)
       } else {
-        return false
+        return condition ? arg2 : arg3
       }
-    } else if (condition instanceof CellError) {
-      return condition
-    } else {
-      return new CellError(ErrorType.VALUE)
-    }
+    })
   }
 
   /**
@@ -131,9 +126,9 @@ export class BooleanPlugin extends FunctionPlugin {
    */
   public and(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND.parameters, 1, (...args) => {
-      if(args.some((arg:Maybe<InternalScalarValue>) => arg===false)) {
+      if(args.some((arg: Maybe<InternalScalarValue>) => arg===false)) {
         return false
-      } else if(args.some((arg:Maybe<InternalScalarValue>) => arg!==undefined)) {
+      } else if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
         return true
       } else {
         return new CellError(ErrorType.VALUE)
@@ -151,9 +146,9 @@ export class BooleanPlugin extends FunctionPlugin {
    */
   public or(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR.parameters, 1, (...args) => {
-      if(args.some((arg:Maybe<InternalScalarValue>) => arg===true)) {
+      if(args.some((arg: Maybe<InternalScalarValue>) => arg===true)) {
         return true
-      } else if(args.some((arg:Maybe<InternalScalarValue>) => arg!==undefined)) {
+      } else if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
         return false
       } else {
         return new CellError(ErrorType.VALUE)
@@ -162,24 +157,13 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public not(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const argValue = this.evaluateAst(ast.args[0], formulaAddress)
-    if (argValue instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    } else {
-      const coercedValue = coerceScalarToBoolean(argValue)
-      if (coercedValue instanceof CellError) {
-        return coercedValue
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.NOT.parameters, (arg) => {
+      if(arg===undefined) {
+        return new CellError(ErrorType.VALUE)
       } else {
-        return !coercedValue
+        return !arg
       }
-    }
+    })
   }
 
   public xor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
@@ -247,45 +231,23 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public iferror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const left: InterpreterValue = this.evaluateAst(ast.args[0], formulaAddress)
-    const right: InterpreterValue = this.evaluateAst(ast.args[1], formulaAddress)
-
-    if (left instanceof SimpleRangeValue || right instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    if (left instanceof CellError) {
-      return right
-    } else {
-      return left
-    }
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IFERROR.parameters, (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
+      if(arg1 instanceof CellError) {
+        return arg2
+      } else {
+        return arg1
+      }
+    })
   }
 
   public ifna(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const left: InterpreterValue = this.evaluateAst(ast.args[0], formulaAddress)
-    const right: InterpreterValue = this.evaluateAst(ast.args[1], formulaAddress)
-
-    if (left instanceof SimpleRangeValue || right instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    if (left instanceof CellError && left.type === ErrorType.NA) {
-      return right
-    } else {
-      return left
-    }
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IFNA.parameters, (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
+      if(arg1 instanceof CellError && arg1.type === ErrorType.NA) {
+        return arg2
+      } else {
+        return arg1
+      }
+    })
   }
 
   public choose(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 3f6651274f..cb1d63e216 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -31,7 +31,7 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
-export type ArgumentTypes = 'string' | 'number' | 'boolean'
+export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar'
 
 export interface FunctionArgumentDefinition {
   argumentType: string,
@@ -157,6 +157,8 @@ export abstract class FunctionPlugin {
         return coerceScalarToString(arg)
       case 'boolean':
         return coerceScalarToBoolean(arg)
+      case 'scalar':
+        return arg
     }
   }
 
@@ -173,12 +175,15 @@ export abstract class FunctionPlugin {
     const coercedArguments: Maybe<InternalScalarValue>[] = []
 
     for (let i = 0; i < argumentDefinitions.length; ++i) {
+      if(args[i] === undefined && argumentDefinitions[i].defaultValue === undefined) {
+        return new CellError(ErrorType.NA)
+      }
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
       if (arg instanceof SimpleRangeValue) {
         return new CellError(ErrorType.VALUE)
       }
       const coercedArg = this.coerceToType(arg, argumentDefinitions[i].argumentType as ArgumentTypes)
-      if (coercedArg instanceof CellError) {
+      if (coercedArg instanceof CellError && argumentDefinitions[i].argumentType !== 'scalar') {
         return coercedArg
       }
       coercedArguments.push(coercedArg)
@@ -199,6 +204,7 @@ export abstract class FunctionPlugin {
 
     let j = 0
     let i = 0
+    //eslint-disable-next-line no-constant-condition
     while(true) {
       const arg = scalarValues[i] ?? argumentDefinitions[j].defaultValue ?? new CellError(ErrorType.NA)
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
diff --git a/test/interpreter/function-if.spec.ts b/test/interpreter/function-if.spec.ts
index 07dc3c42a9..16a338c36a 100644
--- a/test/interpreter/function-if.spec.ts
+++ b/test/interpreter/function-if.spec.ts
@@ -44,6 +44,12 @@ describe('Function IF', () => {
     expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.DIV_BY_ZERO))
   })
 
+  it('passes errors', () => {
+    const engine = HyperFormula.buildFromArray([['=IF(TRUE(), 4/0, "no")']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.DIV_BY_ZERO))
+  })
+
   it('when condition is number', () => {
     const engine = HyperFormula.buildFromArray([['=IF(1, "yes", "no")']])
 

From 381a3096f6380611883762c7bf9a45708c79fde8 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 10:40:05 +0200
Subject: [PATCH 30/97] refactor

---
 src/interpreter/plugin/BooleanPlugin.ts  | 4 ++--
 src/interpreter/plugin/FunctionPlugin.ts | 5 ++++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index ff007cc8ba..ceb8f63f2b 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -273,9 +273,9 @@ export class BooleanPlugin extends FunctionPlugin {
       return vals[0]
     }
 
-    const selector = this.interpreter.arithmeticHelper.coerceToMaybeNumber(vals[0])
+    const selector = this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(vals[0])
 
-    if (selector === undefined || selector != Math.round(selector) || selector < 1 || selector >= n) {
+    if (selector instanceof CellError || selector != Math.round(selector) || selector < 1 || selector >= n) {
       return new CellError(ErrorType.NUM)
     }
     return vals[selector]
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index cb1d63e216..f5b004d1b9 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -206,7 +206,10 @@ export abstract class FunctionPlugin {
     let i = 0
     //eslint-disable-next-line no-constant-condition
     while(true) {
-      const arg = scalarValues[i] ?? argumentDefinitions[j].defaultValue ?? new CellError(ErrorType.NA)
+      const arg = scalarValues[i] ?? argumentDefinitions[j].defaultValue
+      if(arg === undefined) {
+        return new CellError(ErrorType.NA)
+      }
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
       if (coercedArg instanceof CellError) {
         return coercedArg

From 2a61e737a96206d5f2bf4a62f4523b43f363a204 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 12:12:02 +0200
Subject: [PATCH 31/97] xor

---
 src/interpreter/plugin/BooleanPlugin.ts  | 129 ++++++++---------------
 src/interpreter/plugin/FunctionPlugin.ts |  43 +++++++-
 test/interpreter/function-if.spec.ts     |   6 ++
 3 files changed, 91 insertions(+), 87 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index ceb8f63f2b..ac4d499b81 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -44,7 +44,10 @@ export class BooleanPlugin extends FunctionPlugin {
       ],
     },
     'XOR': {
-      method: 'xor'
+      method: 'xor',
+      parameters: [
+        { argumentType: 'boolean' },
+      ],
     },
     'NOT': {
       method: 'not',
@@ -53,7 +56,12 @@ export class BooleanPlugin extends FunctionPlugin {
       ],
     },
     'SWITCH': {
-      method: 'switch'
+      method: 'switch',
+      parameters: [
+        { argumentType: 'noerror' },
+        { argumentType: 'scalar' },
+        { argumentType: 'scalar' },
+      ],
     },
     'IFERROR': {
       method: 'iferror',
@@ -70,7 +78,11 @@ export class BooleanPlugin extends FunctionPlugin {
       ],
     },
     'CHOOSE': {
-      method: 'choose'
+      method: 'choose',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'scalar' },
+      ],
     },
   }
 
@@ -167,67 +179,36 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public xor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    let truesCount = 0
-    let anyFalseValue = false
-    for (const scalarValue of this.iterateOverScalarValues(ast.args, formulaAddress)) {
-      const coercedValue = coerceScalarToBoolean(scalarValue)
-      if (coercedValue instanceof CellError) {
-        return coercedValue
-      } else if (coercedValue === true) {
-        truesCount++
-      } else if (coercedValue === false) {
-        anyFalseValue = true
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.XOR.parameters, 1, (...args) => {
+      if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
+        let cnt = 0
+        args.forEach((arg: Maybe<InternalScalarValue>) => {if(arg===true){cnt++}})
+        // @ts-ignore
+        return (cnt%2) === 1
+      } else {
+        return new CellError(ErrorType.VALUE)
       }
-    }
-    if (anyFalseValue || truesCount > 0) {
-      return (truesCount % 2 === 1)
-    } else {
-      return new CellError(ErrorType.VALUE)
-    }
+    })
   }
 
   public switch(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 3) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const vals: InternalScalarValue[] = []
-    for (const arg of ast.args) {
-      const val: InterpreterValue = this.evaluateAst(arg, formulaAddress)
-      if (val instanceof SimpleRangeValue) {
-        return new CellError(ErrorType.VALUE)
-      }
-      vals.push(val)
-    }
-    const n = vals.length
-    if (vals[0] instanceof CellError) {
-      return vals[0]
-    }
-
-    let i = 1
-    for (; i + 1 < n; i += 2) {
-      if (vals[i] instanceof CellError) {
-        continue
+    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.SWITCH.parameters, 1, (selector, ...args) => {
+      const n = args.length
+      let i  = 0
+      for (; i + 1 < n; i += 2) {
+        if (args[i] instanceof CellError) {
+          continue
+        }
+        if (this.interpreter.arithmeticHelper.compare(selector, args[i] as InternalNoErrorCellValue) === 0) {
+          return args[i+1]
+        }
       }
-      if (this.interpreter.arithmeticHelper.compare(vals[0], vals[i] as InternalNoErrorCellValue) === 0) {
-        return vals[i + 1]
+      if (i < n) {
+        return args[i]
+      } else {
+        return new CellError(ErrorType.NA)
       }
-    }
-    if (i < n) {
-      return vals[i]
-    } else {
-      return new CellError(ErrorType.NA)
-    }
+    })
   }
 
   public iferror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
@@ -251,33 +232,11 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public choose(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const vals: InternalScalarValue[] = []
-    for (const arg of ast.args) {
-      const val: InterpreterValue = this.evaluateAst(arg, formulaAddress)
-      if (val instanceof SimpleRangeValue) {
-        return new CellError(ErrorType.VALUE)
+    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.CHOOSE.parameters, 1,(selector, ...args) => {
+      if(selector !== Math.round(selector) || selector<1 || selector > args.length) {
+        return new CellError(ErrorType.NUM)
       }
-      vals.push(val)
-    }
-
-    const n = vals.length
-
-    if (vals[0] instanceof CellError) {
-      return vals[0]
-    }
-
-    const selector = this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(vals[0])
-
-    if (selector instanceof CellError || selector != Math.round(selector) || selector < 1 || selector >= n) {
-      return new CellError(ErrorType.NUM)
-    }
-    return vals[selector]
+      return args[selector-1]
+    })
   }
 }
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index f5b004d1b9..a5750e4569 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -31,7 +31,7 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
-export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar'
+export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerror'
 
 export interface FunctionArgumentDefinition {
   argumentType: string,
@@ -159,6 +159,8 @@ export abstract class FunctionPlugin {
         return coerceScalarToBoolean(arg)
       case 'scalar':
         return arg
+      case 'noerror':
+        return arg
     }
   }
 
@@ -211,7 +213,7 @@ export abstract class FunctionPlugin {
         return new CellError(ErrorType.NA)
       }
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
-      if (coercedArg instanceof CellError) {
+      if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
         return coercedArg
       }
       coercedArguments.push(coercedArg)
@@ -228,6 +230,43 @@ export abstract class FunctionPlugin {
     return fn(...coercedArguments)
   }
 
+  protected runFunctionWithRepeatedArgNoRanges = (
+    args: Ast[],
+    formulaAddress: SimpleCellAddress,
+    argumentDefinitions: FunctionArgumentDefinition[],
+    repeatedArgs: number,
+    fn: (...arg: any) => InternalScalarValue
+  ) => {
+    const coercedArguments: Maybe<InternalScalarValue>[] = []
+    let j = 0
+    let i = 0
+    //eslint-disable-next-line no-constant-condition
+    while(true) {
+      if(args[i] === undefined && argumentDefinitions[j].defaultValue === undefined) {
+        return new CellError(ErrorType.NA)
+      }
+      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[j].defaultValue)
+      if (arg instanceof SimpleRangeValue) {
+        return new CellError(ErrorType.VALUE)
+      }
+      const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
+      if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
+        return coercedArg
+      }
+      coercedArguments.push(coercedArg)
+      j++
+      i++
+      if(i >= args.length && j === argumentDefinitions.length) {
+        break
+      }
+      if(j===argumentDefinitions.length) {
+        j -= repeatedArgs
+      }
+    }
+
+    return fn(...coercedArguments)
+  }
+
   protected evaluateArgOrDefault = (formulaAddress: SimpleCellAddress, argAst?: Ast, defaultValue?: InternalScalarValue): InterpreterValue => {
     if (argAst !== undefined) {
       return this.evaluateAst(argAst, formulaAddress)
diff --git a/test/interpreter/function-if.spec.ts b/test/interpreter/function-if.spec.ts
index 16a338c36a..98c7cd1aa1 100644
--- a/test/interpreter/function-if.spec.ts
+++ b/test/interpreter/function-if.spec.ts
@@ -50,6 +50,12 @@ describe('Function IF', () => {
     expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.DIV_BY_ZERO))
   })
 
+  it('passes correct value when other arg is an error', () => {
+    const engine = HyperFormula.buildFromArray([['=IF(FALSE(), 4/0, "no")']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual("no")
+  })
+
   it('when condition is number', () => {
     const engine = HyperFormula.buildFromArray([['=IF(1, "yes", "no")']])
 

From 714fea1e54580adc359cd46ee8fef15e8f9c6ff9 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 16:57:36 +0200
Subject: [PATCH 32/97] .

---
 src/interpreter/plugin/BooleanPlugin.ts | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index ac4d499b81..276371ee20 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -182,8 +182,11 @@ export class BooleanPlugin extends FunctionPlugin {
     return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.XOR.parameters, 1, (...args) => {
       if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
         let cnt = 0
-        args.forEach((arg: Maybe<InternalScalarValue>) => {if(arg===true){cnt++}})
-        // @ts-ignore
+        args.forEach((arg: Maybe<InternalScalarValue>) => {
+          if( arg===true ) {
+            cnt++
+          }
+        })
         return (cnt%2) === 1
       } else {
         return new CellError(ErrorType.VALUE)

From a193f36120c5f5031a249dda17110c30a2e7ffb7 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 17:15:56 +0200
Subject: [PATCH 33/97] .

---
 src/interpreter/plugin/BooleanPlugin.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index 276371ee20..81488c9031 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -5,9 +5,8 @@
 
 import {CellError, ErrorType, InternalNoErrorCellValue, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {Maybe} from '../../Maybe'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {coerceScalarToBoolean} from '../ArithmeticHelper'
-import {InterpreterValue, SimpleRangeValue} from '../InterpreterValue'
+import {ProcedureAst} from '../../parser'
+import {InterpreterValue} from '../InterpreterValue'
 import {FunctionPlugin} from './FunctionPlugin'
 
 /**

From 114bf133ba9947dba86c74ec1464cd12b8d1063a Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 17:58:23 +0200
Subject: [PATCH 34/97] merge

---
 src/interpreter/plugin/FunctionPlugin.ts |  38 -------
 src/interpreter/plugin/MedianPlugin.ts   |  40 +++-----
 src/interpreter/plugin/TextPlugin.ts     | 120 -----------------------
 3 files changed, 14 insertions(+), 184 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 959a8113ba..a5750e4569 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -31,15 +31,10 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
-<<<<<<< HEAD
 export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerror'
 
 export interface FunctionArgumentDefinition {
   argumentType: string,
-=======
-export interface FunctionArgumentDefinition {
-  typeCoercionFunction: (arg: InternalScalarValue) => InternalScalarValue,
->>>>>>> develop
   defaultValue?: InternalScalarValue,
 }
 
@@ -95,19 +90,11 @@ export abstract class FunctionPlugin {
   }
 
   protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-<<<<<<< HEAD
     return this.runFunctionWithDefaults(ast.args, formulaAddress, [{ argumentType: 'number'}], fn)
   }
 
   protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
     return this.runFunctionWithDefaults(ast.args, formulaAddress, [{ argumentType: 'string' }], fn)
-=======
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ typeCoercionFunction: this.coerceScalarToNumberOrError }], fn)
-  }
-
-  protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [{ typeCoercionFunction: coerceScalarToString }], fn)
->>>>>>> develop
   }
 
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
@@ -160,7 +147,6 @@ export abstract class FunctionPlugin {
     return value
   }
 
-<<<<<<< HEAD
   public coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
   public coerceToType(arg: InternalScalarValue, coercedType: ArgumentTypes): Maybe<InternalScalarValue> {
@@ -179,11 +165,6 @@ export abstract class FunctionPlugin {
   }
 
   protected runFunctionWithDefaults = (
-=======
-  protected coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
-
-  protected coerceArgumentsWithDefaults = (
->>>>>>> develop
     args: Ast[],
     formulaAddress: SimpleCellAddress,
     argumentDefinitions: FunctionArgumentDefinition[],
@@ -192,7 +173,6 @@ export abstract class FunctionPlugin {
     if (args.length > argumentDefinitions.length) {
       return new CellError(ErrorType.NA)
     }
-<<<<<<< HEAD
 
     const coercedArguments: Maybe<InternalScalarValue>[] = []
 
@@ -282,20 +262,6 @@ export abstract class FunctionPlugin {
       if(j===argumentDefinitions.length) {
         j -= repeatedArgs
       }
-=======
-
-    const coercedArguments: InternalScalarValue[] = []
-    for (let i = 0; i < argumentDefinitions.length; ++i) {
-      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
-      if (arg instanceof SimpleRangeValue) {
-        return new CellError(ErrorType.VALUE)
-      }
-      const coercedArg = argumentDefinitions[i].typeCoercionFunction(arg)
-      if (coercedArg instanceof CellError) {
-        return coercedArg
-      }
-      coercedArguments.push(coercedArg)
->>>>>>> develop
     }
 
     return fn(...coercedArguments)
@@ -305,10 +271,6 @@ export abstract class FunctionPlugin {
     if (argAst !== undefined) {
       return this.evaluateAst(argAst, formulaAddress)
     }
-<<<<<<< HEAD
     return defaultValue ?? new CellError(ErrorType.NA)
-=======
-    return defaultValue || new CellError(ErrorType.NA)
->>>>>>> develop
   }
 }
diff --git a/src/interpreter/plugin/MedianPlugin.ts b/src/interpreter/plugin/MedianPlugin.ts
index 7add71c882..e61194cc62 100644
--- a/src/interpreter/plugin/MedianPlugin.ts
+++ b/src/interpreter/plugin/MedianPlugin.ts
@@ -15,6 +15,9 @@ export class MedianPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'MEDIAN': {
       method: 'median',
+      parameters: [
+        { argumentType: 'noerror' },
+      ],
     },
   }
 
@@ -27,32 +30,17 @@ export class MedianPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public median(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length === 0) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const values: number[] = []
-    for (const scalarValue of this.iterateOverScalarValues(ast.args, formulaAddress)) {
-      if (scalarValue instanceof CellError) {
-        return scalarValue
-      } else if (typeof scalarValue === 'number') {
-        values.push(scalarValue)
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, MedianPlugin.implementedFunctions.MEDIAN.parameters, 1, (...args) => {
+      const values: number[] = args.filter((val: InternalScalarValue) => (typeof val === 'number'))
+      if (values.length === 0) {
+        return new CellError(ErrorType.NUM)
       }
-    }
-
-    if (values.length === 0) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    values.sort((a, b) => (a - b))
-
-    if (values.length % 2 === 0) {
-      return (values[(values.length / 2) - 1] + values[values.length / 2]) / 2
-    } else {
-      return values[Math.floor(values.length / 2)]
-    }
+      values.sort((a, b) => (a - b))
+      if (values.length % 2 === 0) {
+        return (values[(values.length / 2) - 1] + values[values.length / 2]) / 2
+      } else {
+        return values[Math.floor(values.length / 2)]
+      }
+    })
   }
 }
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 0735bb2000..1f85b6c1b1 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -39,7 +39,6 @@ export class TextPlugin extends FunctionPlugin {
       method: 'clean'
     },
     'REPT': {
-<<<<<<< HEAD
       method: 'rept',
       parameters: [
         { argumentType: 'string' },
@@ -75,21 +74,6 @@ export class TextPlugin extends FunctionPlugin {
         { argumentType: 'string' },
         { argumentType: 'number', defaultValue: 1 },
       ],
-=======
-      method: 'rept'
-    },
-    'RIGHT': {
-      method: 'right'
-    },
-    'LEFT': {
-      method: 'left'
-    },
-    'SEARCH': {
-      method: 'search'
-    },
-    'FIND': {
-      method: 'find'
->>>>>>> develop
     }
   }
 
@@ -213,108 +197,4 @@ export class TextPlugin extends FunctionPlugin {
       return index > 0 ? index : new CellError(ErrorType.VALUE)
     })
   }
-
-  public len(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
-      return arg.length
-    })
-  }
-
-  public trim(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
-      return arg.replace(/^ +| +$/g, '').replace(/ +/g, ' ')
-    })
-  }
-
-  public proper(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
-      return arg.replace(/\w\S*/g, word => word.charAt(0).toUpperCase() + word.substr(1).toLowerCase())
-    })
-  }
-
-  public clean(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
-      // eslint-disable-next-line no-control-regex
-      return arg.replace(/[\u0000-\u001F]/g, '')
-    })
-  }
-
-  public rept(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError },
-    ], (text: string, count: number) => {
-      if (count < 0) {
-        return new CellError(ErrorType.VALUE)
-      }
-      return text.repeat(count)
-    })
-  }
-
-  public right(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
-    ], (text: string, length: number) => {
-      if (length < 0) {
-        return new CellError(ErrorType.VALUE)
-      } else if (length === 0) {
-        return ''
-      }
-      return text.slice(-length)
-    })
-  }
-
-  public left(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
-    ], (text: string, length: number) => {
-      if (length < 0) {
-        return new CellError(ErrorType.VALUE)
-      }
-      return text.slice(0, length)
-    })
-  }
-
-  public search(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
-    ], (pattern, text: string, startIndex: number) => {
-      if (startIndex < 1 || startIndex > text.length) {
-        return new CellError(ErrorType.VALUE)
-      }
-
-      const normalizedText = text.substr(startIndex - 1).toLowerCase()
-
-      let index: number
-      if (this.interpreter.arithmeticHelper.requiresRegex(pattern)) {
-        index = this.interpreter.arithmeticHelper.searchString(pattern, normalizedText)
-      } else {
-        index = normalizedText.indexOf(pattern.toLowerCase())
-      }
-
-      index = index + startIndex
-      return index > 0 ? index : new CellError(ErrorType.VALUE)
-    })
-  }
-
-  public find(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.coerceArgumentsWithDefaults(ast.args, formulaAddress, [
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: coerceScalarToString },
-      { typeCoercionFunction: this.coerceScalarToNumberOrError, defaultValue: 1 },
-    ], (pattern, text: string, startIndex: number) => {
-      if (startIndex < 1 || startIndex > text.length) {
-        return new CellError(ErrorType.VALUE)
-      }
-
-      const shiftedText = text.substr(startIndex - 1)
-      const index = shiftedText.indexOf(pattern) + startIndex
-
-      return index > 0 ? index : new CellError(ErrorType.VALUE)
-    })
-  }
 }

From 9131caf587c14e07b86b16c8047eff7edc087121 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 18:03:05 +0200
Subject: [PATCH 35/97] linter

---
 src/interpreter/plugin/BooleanPlugin.ts | 2 +-
 test/interpreter/function-if.spec.ts    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index 81488c9031..ee6153b900 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -234,7 +234,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public choose(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.CHOOSE.parameters, 1,(selector, ...args) => {
+    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.CHOOSE.parameters, 1, (selector, ...args) => {
       if(selector !== Math.round(selector) || selector<1 || selector > args.length) {
         return new CellError(ErrorType.NUM)
       }
diff --git a/test/interpreter/function-if.spec.ts b/test/interpreter/function-if.spec.ts
index 98c7cd1aa1..39fd4dd3f8 100644
--- a/test/interpreter/function-if.spec.ts
+++ b/test/interpreter/function-if.spec.ts
@@ -53,7 +53,7 @@ describe('Function IF', () => {
   it('passes correct value when other arg is an error', () => {
     const engine = HyperFormula.buildFromArray([['=IF(FALSE(), 4/0, "no")']])
 
-    expect(engine.getCellValue(adr('A1'))).toEqual("no")
+    expect(engine.getCellValue(adr('A1'))).toEqual('no')
   })
 
   it('when condition is number', () => {

From e4ba74b8cdbfe02916fb98e28a3212d282196e0f Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 18:04:32 +0200
Subject: [PATCH 36/97] lint

---
 src/interpreter/plugin/MedianPlugin.ts       | 2 +-
 src/interpreter/plugin/TrigonometryPlugin.ts | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/interpreter/plugin/MedianPlugin.ts b/src/interpreter/plugin/MedianPlugin.ts
index e61194cc62..e045b5dddf 100644
--- a/src/interpreter/plugin/MedianPlugin.ts
+++ b/src/interpreter/plugin/MedianPlugin.ts
@@ -4,7 +4,7 @@
  */
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 /**
diff --git a/src/interpreter/plugin/TrigonometryPlugin.ts b/src/interpreter/plugin/TrigonometryPlugin.ts
index 99158a4efd..44212e9fe1 100644
--- a/src/interpreter/plugin/TrigonometryPlugin.ts
+++ b/src/interpreter/plugin/TrigonometryPlugin.ts
@@ -4,8 +4,7 @@
  */
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {SimpleRangeValue} from '../InterpreterValue'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 /**

From 5b120700db989d90bdaac9be7321257023be4ddc Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 18:09:32 +0200
Subject: [PATCH 37/97] countunique

---
 src/interpreter/plugin/CountUniquePlugin.ts | 30 ++++++++++-----------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/interpreter/plugin/CountUniquePlugin.ts b/src/interpreter/plugin/CountUniquePlugin.ts
index 0f5bfe8e83..477625b585 100644
--- a/src/interpreter/plugin/CountUniquePlugin.ts
+++ b/src/interpreter/plugin/CountUniquePlugin.ts
@@ -14,6 +14,9 @@ export class CountUniquePlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'COUNTUNIQUE': {
       method: 'countunique',
+      parameters: [
+        { argumentType: 'scalar' },
+      ],
     },
   }
 
@@ -26,24 +29,19 @@ export class CountUniquePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public countunique(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length === 0) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, CountUniquePlugin.implementedFunctions.COUNTUNIQUE.parameters, 1, (...args: InternalScalarValue[]) => {
+      const valuesSet = new Set<number | string | boolean | EmptyValueType>()
+      const errorsSet = new Set<ErrorType>()
 
-    const valuesSet = new Set<number | string | boolean | EmptyValueType>()
-    const errorsSet = new Set<ErrorType>()
-
-    for (const scalarValue of this.iterateOverScalarValues(ast.args, formulaAddress)) {
-      if (scalarValue instanceof CellError) {
-        errorsSet.add(scalarValue.type)
-      } else if (scalarValue !== '') {
-        valuesSet.add(scalarValue)
+      for (const scalarValue  of args) {
+        if (scalarValue instanceof CellError) {
+          errorsSet.add(scalarValue.type)
+        } else if (scalarValue !== '') {
+          valuesSet.add(scalarValue)
+        }
       }
-    }
 
-    return valuesSet.size + errorsSet.size
+      return valuesSet.size + errorsSet.size
+    })
   }
 }

From f584af3e65b54c8e787adcef61c26e222f70ffdb Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 19:30:41 +0200
Subject: [PATCH 38/97] information plugin

---
 src/interpreter/plugin/InformationPlugin.ts | 108 +++++++-------------
 1 file changed, 36 insertions(+), 72 deletions(-)

diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index d91b608cb5..e163bf6218 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -16,21 +16,39 @@ export class InformationPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISERROR': {
       method: 'iserror',
+      parameters: [
+        { argumentType: 'scalar'}
+      ]
     },
     'ISBLANK': {
       method: 'isblank',
+      parameters: [
+        { argumentType: 'scalar'}
+      ]
     },
     'ISNUMBER': {
       method: 'isnumber',
+      parameters: [
+        { argumentType: 'scalar'}
+      ]
     },
     'ISLOGICAL': {
       method: 'islogical',
+      parameters: [
+        { argumentType: 'scalar'}
+      ]
     },
     'ISTEXT': {
       method: 'istext',
+      parameters: [
+        { argumentType: 'scalar'}
+      ]
     },
     'ISNONTEXT': {
       method: 'isnontext',
+      parameters: [
+        { argumentType: 'scalar'}
+      ]
     },
     'COLUMNS': {
       method: 'columns',
@@ -56,18 +74,9 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public iserror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length != 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    return (arg instanceof CellError)
-
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISERROR.parameters, (arg: InternalScalarValue) =>
+      (arg instanceof CellError)
+    )
   }
 
   /**
@@ -79,18 +88,9 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isblank(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length != 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = ast.args[0]
-    const value = this.evaluateAst(arg, formulaAddress)
-    if (value instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    return (value === EmptyValue)
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISBLANK.parameters, (arg: InternalScalarValue) =>
+      (arg === EmptyValue)
+    )
   }
 
   /**
@@ -102,18 +102,9 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isnumber(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length != 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = ast.args[0]
-    const value = this.evaluateAst(arg, formulaAddress)
-    if (value instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    return (typeof value === 'number')
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNUMBER.parameters, (arg: InternalScalarValue) =>
+      (typeof arg === 'number')
+    )
   }
 
   /**
@@ -125,18 +116,9 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public islogical(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length != 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = ast.args[0]
-    const value = this.evaluateAst(arg, formulaAddress)
-    if (value instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    return (typeof value === 'boolean')
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISLOGICAL.parameters, (arg: InternalScalarValue) =>
+      (typeof arg === 'boolean')
+    )
   }
 
   /**
@@ -148,18 +130,9 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public istext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length != 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = ast.args[0]
-    const value = this.evaluateAst(arg, formulaAddress)
-    if (value instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    return (typeof value === 'string')
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISTEXT.parameters, (arg: InternalScalarValue) =>
+      (typeof arg === 'string')
+    )
   }
 
   /**
@@ -171,18 +144,9 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isnontext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length != 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = ast.args[0]
-    const value = this.evaluateAst(arg, formulaAddress)
-    if (value instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    return (typeof value !== 'string')
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNONTEXT.parameters, (arg: InternalScalarValue) =>
+      (typeof arg !== 'string')
+    )
   }
 
   /**

From c956ca30c8f945b1a6ebff785876cf99a93e82f9 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 23 Jul 2020 21:10:45 +0200
Subject: [PATCH 39/97] columns but its not working

---
 src/interpreter/plugin/FunctionPlugin.ts    | 46 +++++++++++----------
 src/interpreter/plugin/InformationPlugin.ts | 42 +++++++------------
 2 files changed, 40 insertions(+), 48 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index a5750e4569..96825580de 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -31,7 +31,7 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
-export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerror'
+export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerror' | 'range'
 
 export interface FunctionArgumentDefinition {
   argumentType: string,
@@ -149,18 +149,28 @@ export abstract class FunctionPlugin {
 
   public coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
-  public coerceToType(arg: InternalScalarValue, coercedType: ArgumentTypes): Maybe<InternalScalarValue> {
-    switch(coercedType) {
-      case 'number':
-        return this.coerceScalarToNumberOrError(arg)
-      case 'string':
-        return coerceScalarToString(arg)
-      case 'boolean':
-        return coerceScalarToBoolean(arg)
-      case 'scalar':
-        return arg
-      case 'noerror':
+  public coerceToType(arg: InterpreterValue, coercedType: ArgumentTypes): Maybe<InterpreterValue> {
+    if(arg instanceof SimpleRangeValue) {
+      if(coercedType === 'range') {
         return arg
+      } else {
+        return new CellError(ErrorType.VALUE)
+      }
+    } else {
+      switch (coercedType) {
+        case 'number':
+          return this.coerceScalarToNumberOrError(arg)
+        case 'string':
+          return coerceScalarToString(arg)
+        case 'boolean':
+          return coerceScalarToBoolean(arg)
+        case 'scalar':
+          return arg
+        case 'noerror':
+          return arg
+        case 'range':
+          return new CellError(ErrorType.VALUE)
+      }
     }
   }
 
@@ -174,16 +184,13 @@ export abstract class FunctionPlugin {
       return new CellError(ErrorType.NA)
     }
 
-    const coercedArguments: Maybe<InternalScalarValue>[] = []
+    const coercedArguments: Maybe<InterpreterValue>[] = []
 
     for (let i = 0; i < argumentDefinitions.length; ++i) {
       if(args[i] === undefined && argumentDefinitions[i].defaultValue === undefined) {
         return new CellError(ErrorType.NA)
       }
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
-      if (arg instanceof SimpleRangeValue) {
-        return new CellError(ErrorType.VALUE)
-      }
       const coercedArg = this.coerceToType(arg, argumentDefinitions[i].argumentType as ArgumentTypes)
       if (coercedArg instanceof CellError && argumentDefinitions[i].argumentType !== 'scalar') {
         return coercedArg
@@ -202,7 +209,7 @@ export abstract class FunctionPlugin {
     fn: (...arg: any) => InternalScalarValue
   ) => {
     const scalarValues: InternalScalarValue[] = [...this.iterateOverScalarValues(args, formulaAddress)]
-    const coercedArguments: Maybe<InternalScalarValue>[] = []
+    const coercedArguments: Maybe<InterpreterValue>[] = []
 
     let j = 0
     let i = 0
@@ -237,7 +244,7 @@ export abstract class FunctionPlugin {
     repeatedArgs: number,
     fn: (...arg: any) => InternalScalarValue
   ) => {
-    const coercedArguments: Maybe<InternalScalarValue>[] = []
+    const coercedArguments: Maybe<InterpreterValue>[] = []
     let j = 0
     let i = 0
     //eslint-disable-next-line no-constant-condition
@@ -246,9 +253,6 @@ export abstract class FunctionPlugin {
         return new CellError(ErrorType.NA)
       }
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[j].defaultValue)
-      if (arg instanceof SimpleRangeValue) {
-        return new CellError(ErrorType.VALUE)
-      }
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
       if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
         return coercedArg
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index e163bf6218..b76b4fb2cd 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -5,7 +5,7 @@
 
 import {AbsoluteCellRange} from '../../AbsoluteCellRange'
 import {CellError, EmptyValue, ErrorType, InternalCellValue, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {AstNodeType, CellRangeAst, ProcedureAst} from '../../parser'
 import {SimpleRangeValue} from '../InterpreterValue'
 import {FunctionPlugin} from './FunctionPlugin'
 
@@ -54,11 +54,17 @@ export class InformationPlugin extends FunctionPlugin {
       method: 'columns',
       isDependentOnSheetStructureChange: true,
       doesNotNeedArgumentsToBeComputed: true,
+      parameters: [
+        { argumentType: 'range'}
+      ],
     },
     'ROWS': {
       method: 'rows',
       isDependentOnSheetStructureChange: true,
       doesNotNeedArgumentsToBeComputed: true,
+      parameters: [
+        { argumentType: 'range'}
+      ],
     },
     'INDEX': {
       method: 'index',
@@ -157,20 +163,11 @@ export class InformationPlugin extends FunctionPlugin {
    * @param ast
    * @param formulaAddress
    */
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public columns(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const rangeAst = ast.args[0]
-    if (rangeAst.type === AstNodeType.CELL_RANGE) {
-      return (rangeAst.end.col - rangeAst.start.col + 1)
-    } else {
-      return new CellError(ErrorType.VALUE)
-    }
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.COLUMNS.parameters, () => {
+      const rangeAst = ast.args[0] as CellRangeAst
+      return rangeAst.end.col - rangeAst.start.col + 1
+    })
   }
 
   /**
@@ -181,20 +178,11 @@ export class InformationPlugin extends FunctionPlugin {
    * @param ast
    * @param formulaAddress
    */
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public rows(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const rangeAst = ast.args[0]
-    if (rangeAst.type === AstNodeType.CELL_RANGE) {
-      return (rangeAst.end.row - rangeAst.start.row + 1)
-    } else {
-      return new CellError(ErrorType.VALUE)
-    }
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ROWS.parameters, () => {
+      const rangeAst = ast.args[0] as CellRangeAst
+      return rangeAst.end.row - rangeAst.start.row + 1
+    })
   }
 
   public index(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalCellValue {

From fbab7c0461fa1e35a70e02b2df9097ca2a8a3075 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Fri, 24 Jul 2020 11:16:27 +0200
Subject: [PATCH 40/97] .

---
 src/interpreter/plugin/InformationPlugin.ts | 44 +++++++++++++--------
 1 file changed, 27 insertions(+), 17 deletions(-)

diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index b76b4fb2cd..32a817cbf2 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -5,8 +5,7 @@
 
 import {AbsoluteCellRange} from '../../AbsoluteCellRange'
 import {CellError, EmptyValue, ErrorType, InternalCellValue, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, CellRangeAst, ProcedureAst} from '../../parser'
-import {SimpleRangeValue} from '../InterpreterValue'
+import {AstNodeType, ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 /**
@@ -54,17 +53,11 @@ export class InformationPlugin extends FunctionPlugin {
       method: 'columns',
       isDependentOnSheetStructureChange: true,
       doesNotNeedArgumentsToBeComputed: true,
-      parameters: [
-        { argumentType: 'range'}
-      ],
     },
     'ROWS': {
       method: 'rows',
       isDependentOnSheetStructureChange: true,
       doesNotNeedArgumentsToBeComputed: true,
-      parameters: [
-        { argumentType: 'range'}
-      ],
     },
     'INDEX': {
       method: 'index',
@@ -154,7 +147,6 @@ export class InformationPlugin extends FunctionPlugin {
       (typeof arg !== 'string')
     )
   }
-
   /**
    * Corresponds to COLUMNS(range)
    *
@@ -163,11 +155,20 @@ export class InformationPlugin extends FunctionPlugin {
    * @param ast
    * @param formulaAddress
    */
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public columns(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.COLUMNS.parameters, () => {
-      const rangeAst = ast.args[0] as CellRangeAst
-      return rangeAst.end.col - rangeAst.start.col + 1
-    })
+    if (ast.args.length !== 1) {
+      return new CellError(ErrorType.NA)
+    }
+    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
+      return new CellError(ErrorType.NUM)
+    }
+    const rangeAst = ast.args[0]
+    if (rangeAst.type === AstNodeType.CELL_RANGE) {
+      return (rangeAst.end.col - rangeAst.start.col + 1)
+    } else {
+      return new CellError(ErrorType.VALUE)
+    }
   }
 
   /**
@@ -178,11 +179,20 @@ export class InformationPlugin extends FunctionPlugin {
    * @param ast
    * @param formulaAddress
    */
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public rows(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ROWS.parameters, () => {
-      const rangeAst = ast.args[0] as CellRangeAst
-      return rangeAst.end.row - rangeAst.start.row + 1
-    })
+    if (ast.args.length !== 1) {
+      return new CellError(ErrorType.NA)
+    }
+    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
+      return new CellError(ErrorType.NUM)
+    }
+    const rangeAst = ast.args[0]
+    if (rangeAst.type === AstNodeType.CELL_RANGE) {
+      return (rangeAst.end.row - rangeAst.start.row + 1)
+    } else {
+      return new CellError(ErrorType.VALUE)
+    }
   }
 
   public index(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalCellValue {

From c5aa0f7f1df9660e61cf83f78ddf7f6ef01b2f22 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Fri, 24 Jul 2020 12:33:42 +0200
Subject: [PATCH 41/97] fix

---
 src/interpreter/plugin/FunctionPlugin.ts | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 96825580de..27fefb55f2 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -154,7 +154,7 @@ export abstract class FunctionPlugin {
       if(coercedType === 'range') {
         return arg
       } else {
-        return new CellError(ErrorType.VALUE)
+        return undefined
       }
     } else {
       switch (coercedType) {
@@ -169,7 +169,7 @@ export abstract class FunctionPlugin {
         case 'noerror':
           return arg
         case 'range':
-          return new CellError(ErrorType.VALUE)
+          return undefined
       }
     }
   }
@@ -192,6 +192,9 @@ export abstract class FunctionPlugin {
       }
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
       const coercedArg = this.coerceToType(arg, argumentDefinitions[i].argumentType as ArgumentTypes)
+      if(coercedArg === undefined) {
+        return new CellError(ErrorType.VALUE)
+      }
       if (coercedArg instanceof CellError && argumentDefinitions[i].argumentType !== 'scalar') {
         return coercedArg
       }
@@ -220,6 +223,9 @@ export abstract class FunctionPlugin {
         return new CellError(ErrorType.NA)
       }
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
+      if(coercedArg === undefined) {
+        new CellError(ErrorType.VALUE)
+      }
       if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
         return coercedArg
       }
@@ -254,6 +260,9 @@ export abstract class FunctionPlugin {
       }
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[j].defaultValue)
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
+      if(coercedArg === undefined) {
+        new CellError(ErrorType.VALUE)
+      }
       if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
         return coercedArg
       }

From ba3dcf8553748f97eeea7a2c545dec31dff30b03 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Fri, 24 Jul 2020 12:46:07 +0200
Subject: [PATCH 42/97] .

---
 src/interpreter/plugin/BooleanPlugin.ts     | 10 +++++-----
 src/interpreter/plugin/CountUniquePlugin.ts |  2 +-
 src/interpreter/plugin/FunctionPlugin.ts    | 18 ++++++++----------
 src/interpreter/plugin/MedianPlugin.ts      |  2 +-
 src/interpreter/plugin/TextPlugin.ts        |  2 +-
 5 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index ee6153b900..5ebf415315 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -136,7 +136,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public and(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND.parameters, 1, (...args) => {
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND.parameters, (...args) => {
       if(args.some((arg: Maybe<InternalScalarValue>) => arg===false)) {
         return false
       } else if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
@@ -156,7 +156,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public or(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR.parameters, 1, (...args) => {
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR.parameters, (...args) => {
       if(args.some((arg: Maybe<InternalScalarValue>) => arg===true)) {
         return true
       } else if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
@@ -178,7 +178,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public xor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.XOR.parameters, 1, (...args) => {
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.XOR.parameters, (...args) => {
       if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
         let cnt = 0
         args.forEach((arg: Maybe<InternalScalarValue>) => {
@@ -194,7 +194,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public switch(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.SWITCH.parameters, 1, (selector, ...args) => {
+    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.SWITCH.parameters, (selector, ...args) => {
       const n = args.length
       let i  = 0
       for (; i + 1 < n; i += 2) {
@@ -234,7 +234,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public choose(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.CHOOSE.parameters, 1, (selector, ...args) => {
+    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.CHOOSE.parameters, (selector, ...args) => {
       if(selector !== Math.round(selector) || selector<1 || selector > args.length) {
         return new CellError(ErrorType.NUM)
       }
diff --git a/src/interpreter/plugin/CountUniquePlugin.ts b/src/interpreter/plugin/CountUniquePlugin.ts
index 477625b585..7f1f683f2b 100644
--- a/src/interpreter/plugin/CountUniquePlugin.ts
+++ b/src/interpreter/plugin/CountUniquePlugin.ts
@@ -29,7 +29,7 @@ export class CountUniquePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public countunique(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, CountUniquePlugin.implementedFunctions.COUNTUNIQUE.parameters, 1, (...args: InternalScalarValue[]) => {
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, CountUniquePlugin.implementedFunctions.COUNTUNIQUE.parameters, (...args: InternalScalarValue[]) => {
       const valuesSet = new Set<number | string | boolean | EmptyValueType>()
       const errorsSet = new Set<ErrorType>()
 
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 27fefb55f2..fdba280aba 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -208,7 +208,6 @@ export abstract class FunctionPlugin {
     args: Ast[],
     formulaAddress: SimpleCellAddress,
     argumentDefinitions: FunctionArgumentDefinition[],
-    repeatedArgs: number,
     fn: (...arg: any) => InternalScalarValue
   ) => {
     const scalarValues: InternalScalarValue[] = [...this.iterateOverScalarValues(args, formulaAddress)]
@@ -232,11 +231,11 @@ export abstract class FunctionPlugin {
       coercedArguments.push(coercedArg)
       j++
       i++
-      if(i >= scalarValues.length && j === argumentDefinitions.length) {
-        break
-      }
       if(j===argumentDefinitions.length) {
-        j -= repeatedArgs
+        if (i >= scalarValues.length) {
+          break
+        }
+        j--
       }
     }
 
@@ -247,7 +246,6 @@ export abstract class FunctionPlugin {
     args: Ast[],
     formulaAddress: SimpleCellAddress,
     argumentDefinitions: FunctionArgumentDefinition[],
-    repeatedArgs: number,
     fn: (...arg: any) => InternalScalarValue
   ) => {
     const coercedArguments: Maybe<InterpreterValue>[] = []
@@ -269,11 +267,11 @@ export abstract class FunctionPlugin {
       coercedArguments.push(coercedArg)
       j++
       i++
-      if(i >= args.length && j === argumentDefinitions.length) {
-        break
-      }
       if(j===argumentDefinitions.length) {
-        j -= repeatedArgs
+        if (i >= args.length) {
+          break
+        }
+        j--
       }
     }
 
diff --git a/src/interpreter/plugin/MedianPlugin.ts b/src/interpreter/plugin/MedianPlugin.ts
index e045b5dddf..1dab992ee7 100644
--- a/src/interpreter/plugin/MedianPlugin.ts
+++ b/src/interpreter/plugin/MedianPlugin.ts
@@ -30,7 +30,7 @@ export class MedianPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public median(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, MedianPlugin.implementedFunctions.MEDIAN.parameters, 1, (...args) => {
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, MedianPlugin.implementedFunctions.MEDIAN.parameters, (...args) => {
       const values: number[] = args.filter((val: InternalScalarValue) => (typeof val === 'number'))
       if (values.length === 0) {
         return new CellError(ErrorType.NUM)
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 1f85b6c1b1..dae5295989 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -86,7 +86,7 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public concatenate(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, TextPlugin.implementedFunctions.CONCATENATE.parameters, 1, (...args) => {
+    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, TextPlugin.implementedFunctions.CONCATENATE.parameters, (...args) => {
       return ''.concat(...args)
     })
   }

From 0f3418251b96d02b1784a0f46b69a0fdb52ca360 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Fri, 24 Jul 2020 17:13:47 +0200
Subject: [PATCH 43/97] minor fix

---
 src/interpreter/plugin/FunctionPlugin.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index fdba280aba..ea3d29de3b 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -223,7 +223,7 @@ export abstract class FunctionPlugin {
       }
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
       if(coercedArg === undefined) {
-        new CellError(ErrorType.VALUE)
+        return new CellError(ErrorType.VALUE)
       }
       if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
         return coercedArg
@@ -259,7 +259,7 @@ export abstract class FunctionPlugin {
       const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[j].defaultValue)
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
       if(coercedArg === undefined) {
-        new CellError(ErrorType.VALUE)
+        return new CellError(ErrorType.VALUE)
       }
       if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
         return coercedArg

From 7294051c3fdff7b1a05e9e490cff032d9cf450b7 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sat, 25 Jul 2020 13:03:37 +0200
Subject: [PATCH 44/97] simplified templates

---
 src/interpreter/ArithmeticHelper.ts          |   8 +-
 src/interpreter/plugin/BooleanPlugin.ts      |  36 ++++---
 src/interpreter/plugin/CountUniquePlugin.ts  |   4 +-
 src/interpreter/plugin/FinancialPlugin.ts    |   8 +-
 src/interpreter/plugin/FunctionPlugin.ts     | 100 +++++--------------
 src/interpreter/plugin/InformationPlugin.ts  |  12 +--
 src/interpreter/plugin/MedianPlugin.ts       |   4 +-
 src/interpreter/plugin/TextPlugin.ts         |  18 ++--
 src/interpreter/plugin/TrigonometryPlugin.ts |   2 +-
 9 files changed, 75 insertions(+), 117 deletions(-)

diff --git a/src/interpreter/ArithmeticHelper.ts b/src/interpreter/ArithmeticHelper.ts
index 970ad07801..08fb88e222 100644
--- a/src/interpreter/ArithmeticHelper.ts
+++ b/src/interpreter/ArithmeticHelper.ts
@@ -225,13 +225,13 @@ export class ArithmeticHelper {
     return this.coerceToMaybeNumber(arg) ?? new CellError(ErrorType.VALUE)
   }
 
-  public coerceToMaybeNumber(arg: InternalNoErrorCellValue): Maybe<number> {
+  public coerceToMaybeNumber(arg: InternalScalarValue): Maybe<number> {
     return this.coerceNonDateScalarToMaybeNumber(arg) ?? (
       typeof arg === 'string' ? this.dateTimeHelper.dateStringToDateNumber(arg) : undefined
     )
   }
 
-  public coerceNonDateScalarToMaybeNumber(arg: InternalNoErrorCellValue): Maybe<number> {
+  public coerceNonDateScalarToMaybeNumber(arg: InternalScalarValue): Maybe<number> {
     if (arg === EmptyValue) {
       return 0
     } else if (typeof arg === 'string' && this.numberLiteralsHelper.isNumber(arg)) {
@@ -290,9 +290,7 @@ export function coerceEmptyToValue(arg: InternalNoErrorCellValue): InternalNoErr
  * @param arg
  */
 export function coerceScalarToBoolean(arg: InternalScalarValue): boolean | CellError | undefined {
-  if (arg instanceof SimpleRangeValue) {
-    return new CellError(ErrorType.VALUE)
-  } else if (arg instanceof CellError || typeof arg === 'boolean') {
+  if (arg instanceof CellError || typeof arg === 'boolean') {
     return arg
   } else if (arg === EmptyValue) {
     return false
diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index 5ebf415315..d33771e1f6 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -33,20 +33,26 @@ export class BooleanPlugin extends FunctionPlugin {
     'AND': {
       method: 'and',
       parameters: [
-        { argumentType: 'boolean' },
+        { argumentType: 'boolean', softCoerce: true },
       ],
+      repeatedArg: true,
+      expandRanges: true,
     },
     'OR': {
       method: 'or',
       parameters: [
-        { argumentType: 'boolean' },
+        { argumentType: 'boolean', softCoerce: true },
       ],
+      repeatedArg: true,
+      expandRanges: true,
     },
     'XOR': {
       method: 'xor',
       parameters: [
-        { argumentType: 'boolean' },
+        { argumentType: 'boolean', softCoerce: true },
       ],
+      repeatedArg: true,
+      expandRanges: true,
     },
     'NOT': {
       method: 'not',
@@ -61,6 +67,7 @@ export class BooleanPlugin extends FunctionPlugin {
         { argumentType: 'scalar' },
         { argumentType: 'scalar' },
       ],
+      repeatedArg: true,
     },
     'IFERROR': {
       method: 'iferror',
@@ -82,6 +89,7 @@ export class BooleanPlugin extends FunctionPlugin {
         { argumentType: 'number' },
         { argumentType: 'scalar' },
       ],
+      repeatedArg: true,
     },
   }
 
@@ -94,7 +102,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public literalTrue(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.TRUE.parameters, () => true)
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.TRUE, () => true)
   }
 
   /**
@@ -106,7 +114,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public literalFalse(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.FALSE.parameters, () => false)
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.FALSE, () => false)
   }
 
   /**
@@ -118,7 +126,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public conditionalIf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InterpreterValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IF.parameters, (condition, arg2, arg3) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IF, (condition, arg2, arg3) => {
       if(condition===undefined) {
         return new CellError(ErrorType.VALUE)
       } else {
@@ -136,7 +144,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public and(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND.parameters, (...args) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND, (...args) => {
       if(args.some((arg: Maybe<InternalScalarValue>) => arg===false)) {
         return false
       } else if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
@@ -156,7 +164,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public or(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR.parameters, (...args) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR, (...args) => {
       if(args.some((arg: Maybe<InternalScalarValue>) => arg===true)) {
         return true
       } else if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
@@ -168,7 +176,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public not(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.NOT.parameters, (arg) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.NOT, (arg) => {
       if(arg===undefined) {
         return new CellError(ErrorType.VALUE)
       } else {
@@ -178,7 +186,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public xor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.XOR.parameters, (...args) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.XOR, (...args) => {
       if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
         let cnt = 0
         args.forEach((arg: Maybe<InternalScalarValue>) => {
@@ -194,7 +202,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public switch(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.SWITCH.parameters, (selector, ...args) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.SWITCH, (selector, ...args) => {
       const n = args.length
       let i  = 0
       for (; i + 1 < n; i += 2) {
@@ -214,7 +222,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public iferror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IFERROR.parameters, (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IFERROR, (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
       if(arg1 instanceof CellError) {
         return arg2
       } else {
@@ -224,7 +232,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public ifna(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IFNA.parameters, (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IFNA, (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
       if(arg1 instanceof CellError && arg1.type === ErrorType.NA) {
         return arg2
       } else {
@@ -234,7 +242,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public choose(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArgNoRanges(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.CHOOSE.parameters, (selector, ...args) => {
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.CHOOSE, (selector, ...args) => {
       if(selector !== Math.round(selector) || selector<1 || selector > args.length) {
         return new CellError(ErrorType.NUM)
       }
diff --git a/src/interpreter/plugin/CountUniquePlugin.ts b/src/interpreter/plugin/CountUniquePlugin.ts
index 7f1f683f2b..8dac701166 100644
--- a/src/interpreter/plugin/CountUniquePlugin.ts
+++ b/src/interpreter/plugin/CountUniquePlugin.ts
@@ -17,6 +17,8 @@ export class CountUniquePlugin extends FunctionPlugin {
       parameters: [
         { argumentType: 'scalar' },
       ],
+      repeatedArg: true,
+      expandRanges: true,
     },
   }
 
@@ -29,7 +31,7 @@ export class CountUniquePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public countunique(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, CountUniquePlugin.implementedFunctions.COUNTUNIQUE.parameters, (...args: InternalScalarValue[]) => {
+    return this.runFunction(ast.args, formulaAddress, CountUniquePlugin.implementedFunctions.COUNTUNIQUE, (...args: InternalScalarValue[]) => {
       const valuesSet = new Set<number | string | boolean | EmptyValueType>()
       const errorsSet = new Set<ErrorType>()
 
diff --git a/src/interpreter/plugin/FinancialPlugin.ts b/src/interpreter/plugin/FinancialPlugin.ts
index e31d644d4c..e6a26620d7 100644
--- a/src/interpreter/plugin/FinancialPlugin.ts
+++ b/src/interpreter/plugin/FinancialPlugin.ts
@@ -55,19 +55,19 @@ export class FinancialPlugin extends FunctionPlugin {
   }
 
   public pmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.PMT.parameters, pmtCore)
+    return this.runFunction(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.PMT, pmtCore)
   }
 
   public ipmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.IPMT.parameters, ipmtCore)
+    return this.runFunction(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.IPMT, ipmtCore)
   }
 
   public ppmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.PPMT.parameters, ppmtCore)
+    return this.runFunction(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.PPMT, ppmtCore)
   }
 
   public fv(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.FV.parameters, fvCore)
+    return this.runFunction(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.FV, fvCore)
   }
 }
 
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index ea3d29de3b..0d1ccd5086 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -36,6 +36,7 @@ export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerro
 export interface FunctionArgumentDefinition {
   argumentType: string,
   defaultValue?: InternalScalarValue,
+  softCoerce?: boolean
 }
 
 export type PluginFunctionType = (ast: ProcedureAst, formulaAddress: SimpleCellAddress) => InternalScalarValue
@@ -90,11 +91,11 @@ export abstract class FunctionPlugin {
   }
 
   protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, [{ argumentType: 'number'}], fn)
+    return this.runFunction(ast.args, formulaAddress, {parameters: [{ argumentType: 'number'}]}, fn)
   }
 
   protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, [{ argumentType: 'string' }], fn)
+    return this.runFunction(ast.args, formulaAddress, {parameters: [{ argumentType: 'string' }]}, fn)
   }
 
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
@@ -174,108 +175,53 @@ export abstract class FunctionPlugin {
     }
   }
 
-  protected runFunctionWithDefaults = (
+  protected runFunction = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
-    argumentDefinitions: FunctionArgumentDefinition[],
+    functionDefinition: any,
     fn: (...arg: any) => InternalScalarValue
   ) => {
-    if (args.length > argumentDefinitions.length) {
-      return new CellError(ErrorType.NA)
-    }
-
-    const coercedArguments: Maybe<InterpreterValue>[] = []
-
-    for (let i = 0; i < argumentDefinitions.length; ++i) {
-      if(args[i] === undefined && argumentDefinitions[i].defaultValue === undefined) {
-        return new CellError(ErrorType.NA)
-      }
-      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[i].defaultValue)
-      const coercedArg = this.coerceToType(arg, argumentDefinitions[i].argumentType as ArgumentTypes)
-      if(coercedArg === undefined) {
-        return new CellError(ErrorType.VALUE)
-      }
-      if (coercedArg instanceof CellError && argumentDefinitions[i].argumentType !== 'scalar') {
-        return coercedArg
-      }
-      coercedArguments.push(coercedArg)
+    const argumentDefinitions: FunctionArgumentDefinition[] = functionDefinition.parameters
+    let scalarValues: InterpreterValue[]
+    if(functionDefinition.expandRanges) {
+      scalarValues = [...this.iterateOverScalarValues(args, formulaAddress)]
+    } else {
+      scalarValues = args.map((ast) => this.evaluateAst(ast, formulaAddress))
     }
-
-    return fn(...coercedArguments)
-  }
-
-  protected runFunctionWithRepeatedArg = (
-    args: Ast[],
-    formulaAddress: SimpleCellAddress,
-    argumentDefinitions: FunctionArgumentDefinition[],
-    fn: (...arg: any) => InternalScalarValue
-  ) => {
-    const scalarValues: InternalScalarValue[] = [...this.iterateOverScalarValues(args, formulaAddress)]
     const coercedArguments: Maybe<InterpreterValue>[] = []
 
+    let argCoerceFailure: Maybe<CellError> = undefined
     let j = 0
     let i = 0
     //eslint-disable-next-line no-constant-condition
     while(true) {
-      const arg = scalarValues[i] ?? argumentDefinitions[j].defaultValue
-      if(arg === undefined) {
-        return new CellError(ErrorType.NA)
-      }
-      const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
-      if(coercedArg === undefined) {
-        return new CellError(ErrorType.VALUE)
-      }
-      if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
-        return coercedArg
-      }
-      coercedArguments.push(coercedArg)
-      j++
-      i++
       if(j===argumentDefinitions.length) {
         if (i >= scalarValues.length) {
           break
         }
-        j--
+        if(functionDefinition.repeatedArg) {
+          j--
+        } else {
+          return new CellError(ErrorType.NA)
+        }
       }
-    }
-
-    return fn(...coercedArguments)
-  }
-
-  protected runFunctionWithRepeatedArgNoRanges = (
-    args: Ast[],
-    formulaAddress: SimpleCellAddress,
-    argumentDefinitions: FunctionArgumentDefinition[],
-    fn: (...arg: any) => InternalScalarValue
-  ) => {
-    const coercedArguments: Maybe<InterpreterValue>[] = []
-    let j = 0
-    let i = 0
-    //eslint-disable-next-line no-constant-condition
-    while(true) {
-      if(args[i] === undefined && argumentDefinitions[j].defaultValue === undefined) {
+      const arg = scalarValues[i] ?? argumentDefinitions[j]?.defaultValue
+      if(arg === undefined) {
         return new CellError(ErrorType.NA)
       }
-      const arg = this.evaluateArgOrDefault(formulaAddress, args[i], argumentDefinitions[j].defaultValue)
       const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
-      if(coercedArg === undefined) {
-        return new CellError(ErrorType.VALUE)
+      if(coercedArg === undefined && !argumentDefinitions[j].softCoerce) {
+        argCoerceFailure = argCoerceFailure ?? (new CellError(ErrorType.VALUE))
       }
       if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
-        return coercedArg
+        argCoerceFailure = argCoerceFailure ?? coercedArg
       }
       coercedArguments.push(coercedArg)
       j++
       i++
-      if(j===argumentDefinitions.length) {
-        if (i >= args.length) {
-          break
-        }
-        j--
-      }
     }
 
-    return fn(...coercedArguments)
+    return argCoerceFailure ?? fn(...coercedArguments)
   }
 
   protected evaluateArgOrDefault = (formulaAddress: SimpleCellAddress, argAst?: Ast, defaultValue?: InternalScalarValue): InterpreterValue => {
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 32a817cbf2..99b9b2828a 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -73,7 +73,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public iserror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISERROR.parameters, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISERROR, (arg: InternalScalarValue) =>
       (arg instanceof CellError)
     )
   }
@@ -87,7 +87,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isblank(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISBLANK.parameters, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISBLANK, (arg: InternalScalarValue) =>
       (arg === EmptyValue)
     )
   }
@@ -101,7 +101,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isnumber(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNUMBER.parameters, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNUMBER, (arg: InternalScalarValue) =>
       (typeof arg === 'number')
     )
   }
@@ -115,7 +115,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public islogical(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISLOGICAL.parameters, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISLOGICAL, (arg: InternalScalarValue) =>
       (typeof arg === 'boolean')
     )
   }
@@ -129,7 +129,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public istext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISTEXT.parameters, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISTEXT, (arg: InternalScalarValue) =>
       (typeof arg === 'string')
     )
   }
@@ -143,7 +143,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isnontext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNONTEXT.parameters, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNONTEXT, (arg: InternalScalarValue) =>
       (typeof arg !== 'string')
     )
   }
diff --git a/src/interpreter/plugin/MedianPlugin.ts b/src/interpreter/plugin/MedianPlugin.ts
index 1dab992ee7..11f7cba99d 100644
--- a/src/interpreter/plugin/MedianPlugin.ts
+++ b/src/interpreter/plugin/MedianPlugin.ts
@@ -18,6 +18,8 @@ export class MedianPlugin extends FunctionPlugin {
       parameters: [
         { argumentType: 'noerror' },
       ],
+      repeatedArg: true,
+      expandRanges: true,
     },
   }
 
@@ -30,7 +32,7 @@ export class MedianPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public median(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, MedianPlugin.implementedFunctions.MEDIAN.parameters, (...args) => {
+    return this.runFunction(ast.args, formulaAddress, MedianPlugin.implementedFunctions.MEDIAN, (...args) => {
       const values: number[] = args.filter((val: InternalScalarValue) => (typeof val === 'number'))
       if (values.length === 0) {
         return new CellError(ErrorType.NUM)
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index dae5295989..89a6e6279c 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -17,7 +17,9 @@ export class TextPlugin extends FunctionPlugin {
       method: 'concatenate',
       parameters: [
         { argumentType: 'string'}
-      ]
+      ],
+      repeatedArg: true,
+      expandRanges: true,
     },
     'SPLIT': {
       method: 'split',
@@ -86,7 +88,7 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public concatenate(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithRepeatedArg(ast.args, formulaAddress, TextPlugin.implementedFunctions.CONCATENATE.parameters, (...args) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.CONCATENATE, (...args) => {
       return ''.concat(...args)
     })
   }
@@ -100,7 +102,7 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public split(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.SPLIT.parameters, (stringToSplit: string, indexToUse: number) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.SPLIT, (stringToSplit: string, indexToUse: number) => {
       const splittedString = stringToSplit.split(' ')
 
       if (indexToUse >= splittedString.length || indexToUse < 0) {
@@ -137,7 +139,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public rept(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.REPT.parameters, (text: string, count: number) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.REPT, (text: string, count: number) => {
       if (count < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -146,7 +148,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public right(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.RIGHT.parameters, (text: string, length: number) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.RIGHT, (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       } else if (length === 0) {
@@ -157,7 +159,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public left(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.LEFT.parameters, (text: string, length: number) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.LEFT, (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -166,7 +168,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public search(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.SEARCH.parameters, (pattern, text: string, startIndex: number) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.SEARCH, (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }
@@ -186,7 +188,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public find(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, TextPlugin.implementedFunctions.FIND.parameters, (pattern, text: string, startIndex: number) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.FIND, (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }
diff --git a/src/interpreter/plugin/TrigonometryPlugin.ts b/src/interpreter/plugin/TrigonometryPlugin.ts
index 44212e9fe1..c2cae091e9 100644
--- a/src/interpreter/plugin/TrigonometryPlugin.ts
+++ b/src/interpreter/plugin/TrigonometryPlugin.ts
@@ -88,7 +88,7 @@ export class TrigonometryPlugin extends FunctionPlugin {
   }
 
   public atan2(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ATAN2.parameters, Math.atan2)
+    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ATAN2, Math.atan2)
   }
 
   public ctg(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {

From 65caf1f6bb3b8e642e3f0feee96189d0b08e6afd Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sat, 25 Jul 2020 13:32:59 +0200
Subject: [PATCH 45/97] linter + typing

---
 src/interpreter/plugin/FunctionPlugin.ts | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 0d1ccd5086..a2d30780b2 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -3,6 +3,7 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
+import assert from 'assert'
 import {AbsoluteCellRange} from '../../AbsoluteCellRange'
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ColumnSearchStrategy} from '../../ColumnSearch/ColumnSearchStrategy'
@@ -20,6 +21,9 @@ export interface ImplementedFunctions {
 
 export interface FunctionMetadata {
   method: string,
+  parameters?: FunctionArgumentDefinition[],
+  repeatedArg?: boolean,
+  expandRanges?: boolean,
   isVolatile?: boolean,
   isDependentOnSheetStructureChange?: boolean,
   doesNotNeedArgumentsToBeComputed?: boolean,
@@ -36,7 +40,7 @@ export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerro
 export interface FunctionArgumentDefinition {
   argumentType: string,
   defaultValue?: InternalScalarValue,
-  softCoerce?: boolean
+  softCoerce?: boolean,
 }
 
 export type PluginFunctionType = (ast: ProcedureAst, formulaAddress: SimpleCellAddress) => InternalScalarValue
@@ -91,11 +95,11 @@ export abstract class FunctionPlugin {
   }
 
   protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, {parameters: [{ argumentType: 'number'}]}, fn)
+    return this.runFunction(ast.args, formulaAddress, {parameters: [{ argumentType: 'number'}]} as FunctionMetadata, fn)
   }
 
   protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, {parameters: [{ argumentType: 'string' }]}, fn)
+    return this.runFunction(ast.args, formulaAddress, {parameters: [{ argumentType: 'string' }]} as FunctionMetadata, fn)
   }
 
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
@@ -178,10 +182,11 @@ export abstract class FunctionPlugin {
   protected runFunction = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
-    functionDefinition: any,
+    functionDefinition: FunctionMetadata,
     fn: (...arg: any) => InternalScalarValue
   ) => {
-    const argumentDefinitions: FunctionArgumentDefinition[] = functionDefinition.parameters
+    const argumentDefinitions: FunctionArgumentDefinition[] = functionDefinition.parameters!
+    assert(argumentDefinitions !== undefined)
     let scalarValues: InterpreterValue[]
     if(functionDefinition.expandRanges) {
       scalarValues = [...this.iterateOverScalarValues(args, formulaAddress)]

From fc5d84fd4640b48a35690170d6ac83376febf72a Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sat, 25 Jul 2020 15:56:29 +0200
Subject: [PATCH 46/97] template simplification

---
 src/interpreter/plugin/AbsPlugin.ts           |  7 +-
 src/interpreter/plugin/CharPlugin.ts          |  5 +-
 src/interpreter/plugin/CodePlugin.ts          |  5 +-
 src/interpreter/plugin/DegreesPlugin.ts       |  5 +-
 src/interpreter/plugin/ErrorFunctionPlugin.ts |  7 +-
 src/interpreter/plugin/ExpPlugin.ts           |  7 +-
 src/interpreter/plugin/FunctionPlugin.ts      | 14 +---
 src/interpreter/plugin/LogarithmPlugin.ts     | 68 ++++++-------------
 src/interpreter/plugin/ModuloPlugin.ts        | 22 +++---
 src/interpreter/plugin/PowerPlugin.ts         | 23 ++-----
 src/interpreter/plugin/RadiansPlugin.ts       |  9 ++-
 src/interpreter/plugin/RoundingPlugin.ts      | 15 +++-
 src/interpreter/plugin/SqrtPlugin.ts          | 11 ++-
 src/interpreter/plugin/TextPlugin.ts          | 28 +++++---
 src/interpreter/plugin/TrigonometryPlugin.ts  | 47 +++++++------
 test/interpreter/function-log.spec.ts         |  6 ++
 16 files changed, 136 insertions(+), 143 deletions(-)

diff --git a/src/interpreter/plugin/AbsPlugin.ts b/src/interpreter/plugin/AbsPlugin.ts
index 148c64faa5..34de534580 100644
--- a/src/interpreter/plugin/AbsPlugin.ts
+++ b/src/interpreter/plugin/AbsPlugin.ts
@@ -11,12 +11,13 @@ export class AbsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ABS': {
       method: 'abs',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
   public abs(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (arg) => {
-      return Math.abs(arg)
-    })
+    return this.runFunction(ast.args, formulaAddress, AbsPlugin.implementedFunctions.ABS, Math.abs)
   }
 }
diff --git a/src/interpreter/plugin/CharPlugin.ts b/src/interpreter/plugin/CharPlugin.ts
index 454d08be6a..e1f6e62c2e 100644
--- a/src/interpreter/plugin/CharPlugin.ts
+++ b/src/interpreter/plugin/CharPlugin.ts
@@ -11,11 +11,14 @@ export class CharPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CHAR': {
       method: 'char',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
   public char(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (value: number) => {
+    return this.runFunction(ast.args, formulaAddress, CharPlugin.implementedFunctions.CHAR,(value: number) => {
       if (value < 1 || value > 255) {
         return new CellError(ErrorType.NUM)
       }
diff --git a/src/interpreter/plugin/CodePlugin.ts b/src/interpreter/plugin/CodePlugin.ts
index 03c6c035f2..9fbc7e7b4e 100644
--- a/src/interpreter/plugin/CodePlugin.ts
+++ b/src/interpreter/plugin/CodePlugin.ts
@@ -11,11 +11,14 @@ export class CodePlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CODE': {
       method: 'code',
+      parameters: [
+        { argumentType: 'string' }
+        ],
     },
   }
 
   public code(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (value: string) => {
+    return this.runFunction(ast.args, formulaAddress, CodePlugin.implementedFunctions.CODE,(value: string) => {
       if (value.length === 0) {
         return new CellError(ErrorType.VALUE)
       }
diff --git a/src/interpreter/plugin/DegreesPlugin.ts b/src/interpreter/plugin/DegreesPlugin.ts
index 69515316c2..328b065b34 100644
--- a/src/interpreter/plugin/DegreesPlugin.ts
+++ b/src/interpreter/plugin/DegreesPlugin.ts
@@ -11,11 +11,14 @@ export class DegreesPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DEGREES': {
       method: 'degrees',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
   public degrees(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (arg) => {
+    return this.runFunction(ast.args, formulaAddress, DegreesPlugin.implementedFunctions.DEGREES,(arg) => {
       return arg * (180 / Math.PI)
     })
   }
diff --git a/src/interpreter/plugin/ErrorFunctionPlugin.ts b/src/interpreter/plugin/ErrorFunctionPlugin.ts
index 7a7cce454a..b14f24cc49 100644
--- a/src/interpreter/plugin/ErrorFunctionPlugin.ts
+++ b/src/interpreter/plugin/ErrorFunctionPlugin.ts
@@ -14,6 +14,9 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
     },
     'ERFC': {
       method: 'erfc',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
@@ -42,9 +45,7 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
   }
 
   public erfc(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (arg: number) => {
-      return erfc(arg)
-    })
+    return this.runFunction(ast.args, formulaAddress, ErrorFunctionPlugin.implementedFunctions.ERFC,erfc)
   }
 }
 
diff --git a/src/interpreter/plugin/ExpPlugin.ts b/src/interpreter/plugin/ExpPlugin.ts
index 2d8f173735..af1286cedd 100644
--- a/src/interpreter/plugin/ExpPlugin.ts
+++ b/src/interpreter/plugin/ExpPlugin.ts
@@ -11,6 +11,9 @@ export class ExpPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'EXP': {
       method: 'exp',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
@@ -23,8 +26,6 @@ export class ExpPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public exp(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (arg) => {
-      return Math.exp(arg)
-    })
+    return this.runFunction(ast.args, formulaAddress, ExpPlugin.implementedFunctions.EXP, Math.exp)
   }
 }
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index a2d30780b2..bbff78d536 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -94,14 +94,6 @@ export abstract class FunctionPlugin {
     return values
   }
 
-  protected templateWithOneCoercedToNumberArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: number) => InternalScalarValue): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, {parameters: [{ argumentType: 'number'}]} as FunctionMetadata, fn)
-  }
-
-  protected templateWithOneCoercedToStringArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (arg: string) => InternalScalarValue): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, {parameters: [{ argumentType: 'string' }]} as FunctionMetadata, fn)
-  }
-
   protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
     if (ast.args.length !== 2) {
       return new CellError(ErrorType.NA)
@@ -198,12 +190,8 @@ export abstract class FunctionPlugin {
     let argCoerceFailure: Maybe<CellError> = undefined
     let j = 0
     let i = 0
-    //eslint-disable-next-line no-constant-condition
-    while(true) {
+    while(i<scalarValues.length || j<argumentDefinitions.length) {
       if(j===argumentDefinitions.length) {
-        if (i >= scalarValues.length) {
-          break
-        }
         if(functionDefinition.repeatedArg) {
           j--
         } else {
diff --git a/src/interpreter/plugin/LogarithmPlugin.ts b/src/interpreter/plugin/LogarithmPlugin.ts
index 2187c3517d..6154690806 100644
--- a/src/interpreter/plugin/LogarithmPlugin.ts
+++ b/src/interpreter/plugin/LogarithmPlugin.ts
@@ -13,70 +13,40 @@ export class LogarithmPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'LOG10': {
       method: 'log10',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'LOG': {
       method: 'log',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 10 },
+      ],
     },
     'LN': {
       method: 'ln',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
   public log10(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (arg) => {
-      if (arg > 0) {
-        return Math.log10(arg)
-      } else {
-        return new CellError(ErrorType.NUM)
-      }
-    })
+    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LOG10, Math.log10)
   }
 
   public log(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 1 || ast.args.length > 2) {
-      return new CellError(ErrorType.NA)
-    }
-
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let coercedLogarithmicBase
-    if (ast.args[1]) {
-      const logarithmicBase = this.evaluateAst(ast.args[1], formulaAddress)
-      if (logarithmicBase instanceof SimpleRangeValue) {
-        return new CellError(ErrorType.VALUE)
-      }
-      coercedLogarithmicBase = this.coerceScalarToNumberOrError(logarithmicBase)
-    } else {
-      coercedLogarithmicBase = 10
-    }
-
-    const coercedArg = this.coerceScalarToNumberOrError(arg)
-    if (coercedArg instanceof CellError) {
-      return coercedArg
-    } else if (coercedLogarithmicBase instanceof CellError) {
-      return coercedLogarithmicBase
-    } else {
-      if (coercedArg > 0 && coercedLogarithmicBase > 0) {
-        return (Math.log(coercedArg) / Math.log(coercedLogarithmicBase))
-      } else {
-        return new CellError(ErrorType.NUM)
-      }
-    }
+    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LOG, (arg: number, base: number) => {
+        if(arg > 0 && base > 0) {
+          return Math.log(arg) / Math.log(base)
+        } else {
+          return new CellError(ErrorType.NUM)
+        }
+      })
   }
 
   public ln(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (arg) => {
-      if (arg > 0) {
-        return Math.log(arg)
-      } else {
-        return new CellError(ErrorType.NUM)
-      }
-    })
+    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LN,Math.log)
   }
 }
diff --git a/src/interpreter/plugin/ModuloPlugin.ts b/src/interpreter/plugin/ModuloPlugin.ts
index 5e2e9e998f..e5f5ea3e35 100644
--- a/src/interpreter/plugin/ModuloPlugin.ts
+++ b/src/interpreter/plugin/ModuloPlugin.ts
@@ -11,20 +11,20 @@ export class ModuloPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'MOD': {
       method: 'mod',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+      ],
     },
   }
 
   public mod(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    const validationResult = this.validateTwoNumericArguments(ast, formulaAddress)
-    if (validationResult instanceof CellError) {
-      return validationResult
-    }
-    const [dividend, divisor] = validationResult
-
-    if (divisor === 0) {
-      return new CellError(ErrorType.DIV_BY_ZERO)
-    }
-
-    return dividend % divisor
+    return this.runFunction(ast.args, formulaAddress, ModuloPlugin.implementedFunctions.MOD, (dividend: number, divisor: number) => {
+      if (divisor === 0) {
+        return new CellError(ErrorType.DIV_BY_ZERO)
+      } else {
+        return dividend % divisor
+      }
+    })
   }
 }
diff --git a/src/interpreter/plugin/PowerPlugin.ts b/src/interpreter/plugin/PowerPlugin.ts
index 5d90ad65cc..53150065b3 100644
--- a/src/interpreter/plugin/PowerPlugin.ts
+++ b/src/interpreter/plugin/PowerPlugin.ts
@@ -11,27 +11,14 @@ export class PowerPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'POWER': {
       method: 'power',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number' },
+      ],
     },
   }
 
   public power(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    const validationResult = this.validateTwoNumericArguments(ast, formulaAddress)
-
-    if (validationResult instanceof CellError) {
-      return validationResult
-    }
-
-    const [coercedBase, coercedExponent] = validationResult
-
-    if (coercedBase === 0 && coercedExponent < 0) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const value = Math.pow(coercedBase, coercedExponent)
-    if (!Number.isFinite(value)) {
-      return new CellError(ErrorType.NUM)
-    } else {
-      return value
-    }
+    return this.runFunction(ast.args, formulaAddress, PowerPlugin.implementedFunctions.POWER, Math.pow)
   }
 }
diff --git a/src/interpreter/plugin/RadiansPlugin.ts b/src/interpreter/plugin/RadiansPlugin.ts
index c7d06318c1..e673b84b4b 100644
--- a/src/interpreter/plugin/RadiansPlugin.ts
+++ b/src/interpreter/plugin/RadiansPlugin.ts
@@ -11,12 +11,15 @@ export class RadiansPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'RADIANS': {
       method: 'radians',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
   public radians(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (arg) => {
-      return arg * (Math.PI / 180)
-    })
+    return this.runFunction(ast.args, formulaAddress, RadiansPlugin.implementedFunctions.RADIANS,
+      (arg) => arg * (Math.PI / 180)
+    )
   }
 }
diff --git a/src/interpreter/plugin/RoundingPlugin.ts b/src/interpreter/plugin/RoundingPlugin.ts
index bbe2e4222b..a13c488798 100644
--- a/src/interpreter/plugin/RoundingPlugin.ts
+++ b/src/interpreter/plugin/RoundingPlugin.ts
@@ -36,12 +36,21 @@ export class RoundingPlugin extends FunctionPlugin {
     },
     'INT': {
       method: 'intFunc',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'EVEN': {
       method: 'even',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'ODD': {
       method: 'odd',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'CEILING': {
       method: 'ceiling',
@@ -86,7 +95,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public intFunc(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.INT, (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -Math.floor(-coercedNumberToRound)
       } else {
@@ -96,7 +105,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public even(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.EVEN,(coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -findNextEvenNumber(-coercedNumberToRound)
       } else {
@@ -106,7 +115,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public odd(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ODD,(coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -findNextOddNumber(-coercedNumberToRound)
       } else {
diff --git a/src/interpreter/plugin/SqrtPlugin.ts b/src/interpreter/plugin/SqrtPlugin.ts
index b3f2a278c2..93734de57b 100644
--- a/src/interpreter/plugin/SqrtPlugin.ts
+++ b/src/interpreter/plugin/SqrtPlugin.ts
@@ -11,16 +11,13 @@ export class SqrtPlugin extends  FunctionPlugin {
   public static implementedFunctions = {
     'SQRT': {
       method: 'sqrt',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
   public sqrt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (input: number) => {
-      if (input < 0) {
-        return new CellError(ErrorType.NUM)
-      } else {
-        return Math.sqrt(input)
-      }
-    })
+    return this.runFunction(ast.args, formulaAddress, SqrtPlugin.implementedFunctions.SQRT, Math.sqrt)
   }
 }
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 89a6e6279c..7db5dd3c38 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -29,16 +29,28 @@ export class TextPlugin extends FunctionPlugin {
       ],
     },
     'LEN': {
-      method: 'len'
+      method: 'len',
+      parameters: [
+        { argumentType: 'string'}
+      ],
     },
     'TRIM': {
-      method: 'trim'
+      method: 'trim',
+      parameters: [
+        { argumentType: 'string'}
+      ],
     },
     'PROPER': {
-      method: 'proper'
+      method: 'proper',
+      parameters: [
+        { argumentType: 'string'}
+      ],
     },
     'CLEAN': {
-      method: 'clean'
+      method: 'clean',
+      parameters: [
+        { argumentType: 'string'}
+      ],
     },
     'REPT': {
       method: 'rept',
@@ -114,25 +126,25 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public len(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.LEN, (arg: string) => {
       return arg.length
     })
   }
 
   public trim(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.TRIM, (arg: string) => {
       return arg.replace(/^ +| +$/g, '').replace(/ +/g, ' ')
     })
   }
 
   public proper(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.PROPER, (arg: string) => {
       return arg.replace(/\w\S*/g, word => word.charAt(0).toUpperCase() + word.substr(1).toLowerCase())
     })
   }
 
   public clean(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToStringArgument(ast, formulaAddress, (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.CLEAN, (arg: string) => {
       // eslint-disable-next-line no-control-regex
       return arg.replace(/[\u0000-\u001F]/g, '')
     })
diff --git a/src/interpreter/plugin/TrigonometryPlugin.ts b/src/interpreter/plugin/TrigonometryPlugin.ts
index c2cae091e9..4b6365f125 100644
--- a/src/interpreter/plugin/TrigonometryPlugin.ts
+++ b/src/interpreter/plugin/TrigonometryPlugin.ts
@@ -15,21 +15,39 @@ export class TrigonometryPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ACOS': {
       method: 'acos',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'ASIN': {
       method: 'asin',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'COS': {
       method: 'cos',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'SIN': {
       method: 'sin',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'TAN': {
       method: 'tan',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'ATAN': {
       method: 'atan',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
     'ATAN2': {
       method: 'atan2',
@@ -40,6 +58,9 @@ export class TrigonometryPlugin extends FunctionPlugin {
     },
     'COT': {
       method: 'ctg',
+      parameters: [
+        { argumentType: 'number' }
+      ],
     },
   }
 
@@ -52,39 +73,27 @@ export class TrigonometryPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public acos(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedArg) => {
-      if (-1 <= coercedArg && coercedArg <= 1) {
-        return Math.acos(coercedArg)
-      } else {
-        return new CellError(ErrorType.NUM)
-      }
-    })
+    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ACOS, Math.acos)
   }
 
   public asin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedArg) => {
-      if (-1 <= coercedArg && coercedArg <= 1) {
-        return Math.asin(coercedArg)
-      } else {
-        return new CellError(ErrorType.NUM)
-      }
-    })
+    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ASIN, Math.asin)
   }
 
   public cos(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, Math.cos)
+    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.COS, Math.cos)
   }
 
   public sin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, Math.sin)
+    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.SIN, Math.sin)
   }
 
   public tan(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, Math.tan)
+    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.TAN, Math.tan)
   }
 
   public atan(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, Math.atan)
+    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ATAN, Math.atan)
   }
 
   public atan2(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
@@ -92,7 +101,7 @@ export class TrigonometryPlugin extends FunctionPlugin {
   }
 
   public ctg(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithOneCoercedToNumberArgument(ast, formulaAddress, (coercedArg) => {
+    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.COT, (coercedArg) => {
       if (coercedArg === 0) {
         return new CellError(ErrorType.DIV_BY_ZERO)
       } else {
diff --git a/test/interpreter/function-log.spec.ts b/test/interpreter/function-log.spec.ts
index 3c4e976518..b917cac613 100644
--- a/test/interpreter/function-log.spec.ts
+++ b/test/interpreter/function-log.spec.ts
@@ -43,6 +43,12 @@ describe('Function LOG', () => {
     expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NUM))
   })
 
+  it('for 1 base', () => {
+    const engine = HyperFormula.buildFromArray([['=LOG(42, 1)']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NUM))
+  })
+
   it('for negative base', () => {
     const engine = HyperFormula.buildFromArray([['=LOG(42, -42)']])
 

From 32acd0ba5d127c27c6771cf5c5b8f5dd61bed3c9 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sat, 25 Jul 2020 15:59:08 +0200
Subject: [PATCH 47/97] linter

---
 src/interpreter/plugin/CharPlugin.ts          | 2 +-
 src/interpreter/plugin/CodePlugin.ts          | 2 +-
 src/interpreter/plugin/DegreesPlugin.ts       | 2 +-
 src/interpreter/plugin/ErrorFunctionPlugin.ts | 2 +-
 src/interpreter/plugin/LogarithmPlugin.ts     | 2 +-
 src/interpreter/plugin/RoundingPlugin.ts      | 4 ++--
 6 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/interpreter/plugin/CharPlugin.ts b/src/interpreter/plugin/CharPlugin.ts
index e1f6e62c2e..47b60222bf 100644
--- a/src/interpreter/plugin/CharPlugin.ts
+++ b/src/interpreter/plugin/CharPlugin.ts
@@ -18,7 +18,7 @@ export class CharPlugin extends FunctionPlugin {
   }
 
   public char(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, CharPlugin.implementedFunctions.CHAR,(value: number) => {
+    return this.runFunction(ast.args, formulaAddress, CharPlugin.implementedFunctions.CHAR, (value: number) => {
       if (value < 1 || value > 255) {
         return new CellError(ErrorType.NUM)
       }
diff --git a/src/interpreter/plugin/CodePlugin.ts b/src/interpreter/plugin/CodePlugin.ts
index 9fbc7e7b4e..27974d6797 100644
--- a/src/interpreter/plugin/CodePlugin.ts
+++ b/src/interpreter/plugin/CodePlugin.ts
@@ -18,7 +18,7 @@ export class CodePlugin extends FunctionPlugin {
   }
 
   public code(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, CodePlugin.implementedFunctions.CODE,(value: string) => {
+    return this.runFunction(ast.args, formulaAddress, CodePlugin.implementedFunctions.CODE, (value: string) => {
       if (value.length === 0) {
         return new CellError(ErrorType.VALUE)
       }
diff --git a/src/interpreter/plugin/DegreesPlugin.ts b/src/interpreter/plugin/DegreesPlugin.ts
index 328b065b34..8c93d2b8be 100644
--- a/src/interpreter/plugin/DegreesPlugin.ts
+++ b/src/interpreter/plugin/DegreesPlugin.ts
@@ -18,7 +18,7 @@ export class DegreesPlugin extends FunctionPlugin {
   }
 
   public degrees(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, DegreesPlugin.implementedFunctions.DEGREES,(arg) => {
+    return this.runFunction(ast.args, formulaAddress, DegreesPlugin.implementedFunctions.DEGREES, (arg) => {
       return arg * (180 / Math.PI)
     })
   }
diff --git a/src/interpreter/plugin/ErrorFunctionPlugin.ts b/src/interpreter/plugin/ErrorFunctionPlugin.ts
index b14f24cc49..5d597af37d 100644
--- a/src/interpreter/plugin/ErrorFunctionPlugin.ts
+++ b/src/interpreter/plugin/ErrorFunctionPlugin.ts
@@ -45,7 +45,7 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
   }
 
   public erfc(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, ErrorFunctionPlugin.implementedFunctions.ERFC,erfc)
+    return this.runFunction(ast.args, formulaAddress, ErrorFunctionPlugin.implementedFunctions.ERFC, erfc)
   }
 }
 
diff --git a/src/interpreter/plugin/LogarithmPlugin.ts b/src/interpreter/plugin/LogarithmPlugin.ts
index 6154690806..ab44a05863 100644
--- a/src/interpreter/plugin/LogarithmPlugin.ts
+++ b/src/interpreter/plugin/LogarithmPlugin.ts
@@ -47,6 +47,6 @@ export class LogarithmPlugin extends FunctionPlugin {
   }
 
   public ln(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LN,Math.log)
+    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LN, Math.log)
   }
 }
diff --git a/src/interpreter/plugin/RoundingPlugin.ts b/src/interpreter/plugin/RoundingPlugin.ts
index a13c488798..12244e45f5 100644
--- a/src/interpreter/plugin/RoundingPlugin.ts
+++ b/src/interpreter/plugin/RoundingPlugin.ts
@@ -105,7 +105,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public even(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.EVEN,(coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.EVEN, (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -findNextEvenNumber(-coercedNumberToRound)
       } else {
@@ -115,7 +115,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public odd(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ODD,(coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ODD, (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -findNextOddNumber(-coercedNumberToRound)
       } else {

From c9550cbf495b38cdc5e92fea825f70bea2200645 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sat, 25 Jul 2020 17:02:30 +0200
Subject: [PATCH 48/97] .

---
 src/interpreter/plugin/FunctionPlugin.ts |   2 +-
 src/interpreter/plugin/RoundingPlugin.ts | 106 ++++++++---------------
 2 files changed, 35 insertions(+), 73 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index bbff78d536..10bfdd6bb7 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -9,11 +9,11 @@ import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../.
 import {ColumnSearchStrategy} from '../../ColumnSearch/ColumnSearchStrategy'
 import {Config} from '../../Config'
 import {DependencyGraph} from '../../DependencyGraph'
+import {Maybe} from '../../Maybe'
 import {Ast, AstNodeType, ProcedureAst} from '../../parser'
 import {coerceScalarToBoolean, coerceScalarToString} from '../ArithmeticHelper'
 import {Interpreter} from '../Interpreter'
 import {InterpreterValue, SimpleRangeValue} from '../InterpreterValue'
-import {Maybe} from '../../Maybe'
 
 export interface ImplementedFunctions {
   [formulaId: string]: FunctionMetadata,
diff --git a/src/interpreter/plugin/RoundingPlugin.ts b/src/interpreter/plugin/RoundingPlugin.ts
index 12244e45f5..e01fce9c5f 100644
--- a/src/interpreter/plugin/RoundingPlugin.ts
+++ b/src/interpreter/plugin/RoundingPlugin.ts
@@ -24,15 +24,31 @@ export class RoundingPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ROUNDUP': {
       method: 'roundup',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0},
+      ],
     },
     'ROUNDDOWN': {
       method: 'rounddown',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0},
+      ],
     },
     'ROUND': {
       method: 'round',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0},
+      ],
     },
     'TRUNC': {
       method: 'trunc',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0},
+      ],
     },
     'INT': {
       method: 'intFunc',
@@ -54,11 +70,16 @@ export class RoundingPlugin extends FunctionPlugin {
     },
     'CEILING': {
       method: 'ceiling',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 1 },
+        { argumentType: 'number', defaultValue: 0 },
+      ],
     },
   }
 
   public roundup(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.commonArgumentsHandling2(ast, formulaAddress, (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ROUNDDOWN, (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.ceil(-numberToRound * placesMultiplier) / placesMultiplier
@@ -69,7 +90,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public rounddown(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.commonArgumentsHandling2(ast, formulaAddress, (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ROUNDDOWN, (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.floor(-numberToRound * placesMultiplier) / placesMultiplier
@@ -80,7 +101,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public round(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.commonArgumentsHandling2(ast, formulaAddress, (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ROUND, (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.round(-numberToRound * placesMultiplier) / placesMultiplier
@@ -125,79 +146,20 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public ceiling(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 1 || ast.args.length > 3) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const value = this.getNumericArgument(ast, formulaAddress, 0)
-    if (value instanceof CellError) {
-      return value
-    }
-
-    let significance: number | CellError = 1
-    if (ast.args.length >= 2) {
-      significance = this.getNumericArgument(ast, formulaAddress, 1)
-      if (significance instanceof CellError) {
-        return significance
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.CEILING,(value: number, significance: number, mode: number) => {
+      if (significance === 0 || value === 0) {
+        return 0
       }
-    }
 
-    let mode: number | CellError = 0
-    if (ast.args.length === 3) {
-      mode = this.getNumericArgument(ast, formulaAddress, 2)
-      if (mode instanceof CellError) {
-        return mode
+      if ((value > 0) !== (significance > 0) && ast.args.length > 1) {
+        return new CellError(ErrorType.NUM)
       }
-    }
-
-    if (significance === 0 || value === 0) {
-      return 0
-    }
-
-    if ((value > 0) != (significance > 0) && ast.args.length > 1) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    if (mode === 0) {
-      significance = Math.abs(significance)
-    }
 
-    return Math.ceil(value / significance) * significance
-  }
-
-  private commonArgumentsHandling2(ast: ProcedureAst, formulaAddress: SimpleCellAddress, roundingFunction: RoundingFunction): InternalScalarValue {
-    if (ast.args.length < 1 || ast.args.length > 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const numberToRound = this.evaluateAst(ast.args[0], formulaAddress)
-    if (numberToRound instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    let coercedPlaces
-    if (ast.args[1]) {
-      const places = this.evaluateAst(ast.args[1], formulaAddress)
-      if (places instanceof SimpleRangeValue) {
-        return new CellError(ErrorType.VALUE)
+      if (mode === 0) {
+        significance = Math.abs(significance)
       }
-      coercedPlaces = this.coerceScalarToNumberOrError(places)
-    } else {
-      coercedPlaces = 0
-    }
-
-    const coercedNumberToRound = this.coerceScalarToNumberOrError(numberToRound)
-    if (coercedNumberToRound instanceof CellError) {
-      return coercedNumberToRound
-    } else if (coercedPlaces instanceof CellError) {
-      return coercedPlaces
-    } else {
-      return roundingFunction(coercedNumberToRound, coercedPlaces)
-    }
+
+      return Math.ceil(value / significance) * significance
+    })
   }
 }

From c2439be55eb6e66abec7a66995856c850a4424ab Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sat, 25 Jul 2020 17:17:59 +0200
Subject: [PATCH 49/97] .

---
 src/interpreter/plugin/DeltaPlugin.ts    | 28 ++++++------------------
 src/interpreter/plugin/FunctionPlugin.ts | 16 +++++++++-----
 2 files changed, 18 insertions(+), 26 deletions(-)

diff --git a/src/interpreter/plugin/DeltaPlugin.ts b/src/interpreter/plugin/DeltaPlugin.ts
index 43644ccb85..6cfbf84f95 100644
--- a/src/interpreter/plugin/DeltaPlugin.ts
+++ b/src/interpreter/plugin/DeltaPlugin.ts
@@ -11,30 +11,16 @@ export class DeltaPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DELTA': {
       method: 'delta',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: 0 },
+      ],
     },
   }
 
   public delta(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 1 || ast.args.length > 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const left = this.getNumericArgument(ast, formulaAddress, 0)
-    if (left instanceof CellError) {
-      return left
-    }
-
-    let right: number | CellError = 0
-    if (ast.args.length === 2) {
-      right = this.getNumericArgument(ast, formulaAddress, 1)
-      if (right instanceof CellError) {
-        return right
-      }
-    }
-
-    return left === right ? 1 : 0
+    return this.runFunction(ast.args, formulaAddress, DeltaPlugin.implementedFunctions.DELTA, (left: number, right: number) => {
+      return left === right ? 1 : 0
+    })
   }
 }
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 10bfdd6bb7..a60e9ba0ab 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -41,6 +41,8 @@ export interface FunctionArgumentDefinition {
   argumentType: string,
   defaultValue?: InternalScalarValue,
   softCoerce?: boolean,
+  minValue?: number,
+  maxValue?: number,
 }
 
 export type PluginFunctionType = (ast: ProcedureAst, formulaAddress: SimpleCellAddress) => InternalScalarValue
@@ -146,17 +148,21 @@ export abstract class FunctionPlugin {
 
   public coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
-  public coerceToType(arg: InterpreterValue, coercedType: ArgumentTypes): Maybe<InterpreterValue> {
+  public coerceToType(arg: InterpreterValue, coercedType: FunctionArgumentDefinition): Maybe<InterpreterValue> {
     if(arg instanceof SimpleRangeValue) {
-      if(coercedType === 'range') {
+      if(coercedType.argumentType === 'range') {
         return arg
       } else {
         return undefined
       }
     } else {
-      switch (coercedType) {
+      switch (coercedType.argumentType as ArgumentTypes) {
         case 'number':
-          return this.coerceScalarToNumberOrError(arg)
+          const value = this.coerceScalarToNumberOrError(arg)
+          if (typeof value === 'number' && coercedType.maxValue !== undefined && coercedType.minValue !== undefined && (value < coercedType.minValue || value > coercedType.maxValue)) {
+            return new CellError(ErrorType.NUM)
+          }
+          return value
         case 'string':
           return coerceScalarToString(arg)
         case 'boolean':
@@ -202,7 +208,7 @@ export abstract class FunctionPlugin {
       if(arg === undefined) {
         return new CellError(ErrorType.NA)
       }
-      const coercedArg = this.coerceToType(arg, argumentDefinitions[j].argumentType as ArgumentTypes)
+      const coercedArg = this.coerceToType(arg, argumentDefinitions[j])
       if(coercedArg === undefined && !argumentDefinitions[j].softCoerce) {
         argCoerceFailure = argCoerceFailure ?? (new CellError(ErrorType.VALUE))
       }

From 5fbd9d7a6dde35bf169c1e467c61174f16c2ba6e Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sat, 25 Jul 2020 17:24:02 +0200
Subject: [PATCH 50/97] linter

---
 src/interpreter/plugin/FunctionPlugin.ts | 1 +
 src/interpreter/plugin/RoundingPlugin.ts | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index a60e9ba0ab..5176af501a 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -158,6 +158,7 @@ export abstract class FunctionPlugin {
     } else {
       switch (coercedType.argumentType as ArgumentTypes) {
         case 'number':
+          // eslint-disable-next-line no-case-declarations
           const value = this.coerceScalarToNumberOrError(arg)
           if (typeof value === 'number' && coercedType.maxValue !== undefined && coercedType.minValue !== undefined && (value < coercedType.minValue || value > coercedType.maxValue)) {
             return new CellError(ErrorType.NUM)
diff --git a/src/interpreter/plugin/RoundingPlugin.ts b/src/interpreter/plugin/RoundingPlugin.ts
index e01fce9c5f..18eba40037 100644
--- a/src/interpreter/plugin/RoundingPlugin.ts
+++ b/src/interpreter/plugin/RoundingPlugin.ts
@@ -146,7 +146,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public ceiling(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.CEILING,(value: number, significance: number, mode: number) => {
+    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.CEILING, (value: number, significance: number, mode: number) => {
       if (significance === 0 || value === 0) {
         return 0
       }

From cdb09385fef40e4334ab283e1ec4f6764eb3b720 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sun, 26 Jul 2020 13:40:28 +0200
Subject: [PATCH 51/97] more

---
 .../plugin/BitwiseLogicOperationsPlugin.ts    | 33 +++++++++----------
 src/interpreter/plugin/ErrorFunctionPlugin.ts | 30 ++++++-----------
 src/interpreter/plugin/FunctionPlugin.ts      | 16 +++++++--
 3 files changed, 38 insertions(+), 41 deletions(-)

diff --git a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
index 0cfe193525..a83028ed10 100644
--- a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
+++ b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
@@ -11,45 +11,42 @@ export class BitwiseLogicOperationsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'BITAND': {
       method: 'bitand',
+      parameters: [
+        { argumentType: 'integer', minValue: 0 },
+        { argumentType: 'integer', minValue: 0 },
+      ]
     },
     'BITOR': {
       method: 'bitor',
+      parameters: [
+        { argumentType: 'integer', minValue: 0 },
+        { argumentType: 'integer', minValue: 0 },
+      ]
     },
     'BITXOR': {
       method: 'bitxor',
+      parameters: [
+        { argumentType: 'integer', minValue: 0 },
+        { argumentType: 'integer', minValue: 0 },
+      ]
     },
   }
 
   public bitand(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithTwoPositiveIntegerArguments(ast, formulaAddress, (left: number, right: number) => {
+    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITAND, (left: number, right: number) => {
       return left & right
     })
   }
 
   public bitor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithTwoPositiveIntegerArguments(ast, formulaAddress, (left: number, right: number) => {
+    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITOR, (left: number, right: number) => {
       return left | right
     })
   }
 
   public bitxor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.templateWithTwoPositiveIntegerArguments(ast, formulaAddress, (left: number, right: number) => {
+    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITXOR, (left: number, right: number) => {
       return left ^ right
     })
   }
-
-  private templateWithTwoPositiveIntegerArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (left: number, right: number) => InternalScalarValue): InternalScalarValue {
-    const validationResult = this.validateTwoNumericArguments(ast, formulaAddress)
-
-    if (validationResult instanceof CellError) {
-      return validationResult
-    }
-
-    const [coercedLeft, coercedRight] = validationResult
-    if (coercedLeft < 0 || coercedRight < 0 || !Number.isInteger(coercedLeft) || !Number.isInteger(coercedRight)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    return fn(coercedLeft, coercedRight)
-  }
 }
diff --git a/src/interpreter/plugin/ErrorFunctionPlugin.ts b/src/interpreter/plugin/ErrorFunctionPlugin.ts
index 5d597af37d..2ad9d40216 100644
--- a/src/interpreter/plugin/ErrorFunctionPlugin.ts
+++ b/src/interpreter/plugin/ErrorFunctionPlugin.ts
@@ -3,7 +3,8 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {CellError, EmptyValue, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {upperBound} from '../../ColumnSearch/ColumnIndex'
 import {AstNodeType, ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
@@ -11,6 +12,10 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ERF': {
       method: 'erf',
+      parameters: [
+        { argumentType: 'number' },
+        { argumentType: 'number', defaultValue: EmptyValue as InternalScalarValue}, //hacking around since ERF can take 1 or 2 args
+      ],
     },
     'ERFC': {
       method: 'erfc',
@@ -21,27 +26,12 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
   }
 
   public erf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 1 || ast.args.length > 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const lowerBound = this.getNumericArgument(ast, formulaAddress, 0)
-    if (lowerBound instanceof CellError) {
-      return lowerBound
-    }
-
-    if (ast.args.length === 2) {
-      const upperBound = this.getNumericArgument(ast, formulaAddress, 1)
-      if (upperBound instanceof CellError) {
-        return upperBound
+    return this.runFunction(ast.args, formulaAddress, ErrorFunctionPlugin.implementedFunctions.ERF, (lowerBound, upperBound) => {
+      if(ast.args.length === 1) {
+        return erf(lowerBound)
       }
       return erf2(lowerBound, upperBound)
-    }
-
-    return erf(lowerBound)
+    })
   }
 
   public erfc(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 5176af501a..612ea79faf 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -35,7 +35,7 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
-export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerror' | 'range'
+export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerror' | 'range' | 'integer'
 
 export interface FunctionArgumentDefinition {
   argumentType: string,
@@ -157,10 +157,20 @@ export abstract class FunctionPlugin {
       }
     } else {
       switch (coercedType.argumentType as ArgumentTypes) {
+        case 'integer':
         case 'number':
           // eslint-disable-next-line no-case-declarations
           const value = this.coerceScalarToNumberOrError(arg)
-          if (typeof value === 'number' && coercedType.maxValue !== undefined && coercedType.minValue !== undefined && (value < coercedType.minValue || value > coercedType.maxValue)) {
+          if(typeof value !== 'number') {
+            return value
+          }
+          if(coercedType.maxValue !== undefined && value > coercedType.maxValue) {
+            return new CellError(ErrorType.NUM)
+          }
+          if (coercedType.minValue !== undefined && value < coercedType.minValue) {
+            return new CellError(ErrorType.NUM)
+          }
+          if(coercedType.argumentType === 'integer' && !Number.isInteger(value)) {
             return new CellError(ErrorType.NUM)
           }
           return value
@@ -209,7 +219,7 @@ export abstract class FunctionPlugin {
       if(arg === undefined) {
         return new CellError(ErrorType.NA)
       }
-      const coercedArg = this.coerceToType(arg, argumentDefinitions[j])
+      const coercedArg = scalarValues[i] !== undefined ? this.coerceToType(arg, argumentDefinitions[j]) : arg
       if(coercedArg === undefined && !argumentDefinitions[j].softCoerce) {
         argCoerceFailure = argCoerceFailure ?? (new CellError(ErrorType.VALUE))
       }

From 9883e4df39f79e4a0085c969471796085aaeeb77 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Sun, 26 Jul 2020 17:08:55 +0200
Subject: [PATCH 52/97] defaults

---
 src/interpreter/plugin/BitShiftPlugin.ts      | 54 ++++++++-----------
 .../plugin/BitwiseLogicOperationsPlugin.ts    | 18 +++----
 src/interpreter/plugin/ErrorFunctionPlugin.ts | 11 ++--
 src/interpreter/plugin/FunctionPlugin.ts      | 41 ++++----------
 4 files changed, 45 insertions(+), 79 deletions(-)

diff --git a/src/interpreter/plugin/BitShiftPlugin.ts b/src/interpreter/plugin/BitShiftPlugin.ts
index 1d8b20812c..445dd87e7e 100644
--- a/src/interpreter/plugin/BitShiftPlugin.ts
+++ b/src/interpreter/plugin/BitShiftPlugin.ts
@@ -15,59 +15,49 @@ export class BitShiftPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'BITLSHIFT': {
       method: 'bitlshift',
+      parameters: [
+        { argumentType: 'integer', minValue: 0 },
+        { argumentType: 'integer', minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
+      ]
     },
     'BITRSHIFT': {
       method: 'bitrshift',
+      parameters: [
+        { argumentType: 'integer', minValue: 0 },
+        { argumentType: 'integer', minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
+      ]
     },
   }
 
   public bitlshift(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.bitshiftTemplate(ast, formulaAddress, shiftLeft)
+    return this.runFunction(ast.args, formulaAddress, BitShiftPlugin.implementedFunctions.BITLSHIFT, shiftLeft)
   }
 
   public bitrshift(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.bitshiftTemplate(ast, formulaAddress, shiftRight)
-  }
-
-  private bitshiftTemplate(ast: ProcedureAst, formulaAddress: SimpleCellAddress, fn: (value: number, positions: number) => number): InternalScalarValue {
-    const validationResult = this.validateTwoNumericArguments(ast, formulaAddress)
-
-    if (validationResult instanceof CellError) {
-      return validationResult
-    }
-
-    const [coercedValue, coercedPositions] = validationResult
-
-    if (coercedValue < 0 || !Number.isInteger(coercedValue) || !Number.isInteger(coercedPositions)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    if (coercedPositions < SHIFT_MIN_POSITIONS || coercedPositions > SHIFT_MAX_POSITIONS) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const result = fn(coercedValue, coercedPositions)
-
-    if (result > MAX_48BIT_INTEGER) {
-      return new CellError(ErrorType.NUM)
-    } else {
-      return result
-    }
+    return this.runFunction(ast.args, formulaAddress, BitShiftPlugin.implementedFunctions.BITRSHIFT, shiftRight)
   }
 }
 
-function shiftLeft(value: number, positions: number): number {
+function shiftLeft(value: number, positions: number): number | CellError {
   if (positions < 0) {
     return shiftRight(value, -positions)
   } else {
-    return value * Math.pow(2, positions)
+    return validate(value * Math.pow(2, positions))
   }
 }
 
-function shiftRight(value: number, positions: number): number {
+function shiftRight(value: number, positions: number): number | CellError {
   if (positions < 0) {
     return shiftLeft(value, -positions)
   } else {
-    return Math.floor(value / Math.pow(2, positions))
+    return validate(Math.floor(value / Math.pow(2, positions)))
+  }
+}
+
+function validate(result: number): number | CellError {
+  if (result > MAX_48BIT_INTEGER) {
+    return new CellError(ErrorType.NUM)
+  } else {
+    return result
   }
 }
diff --git a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
index a83028ed10..c4bf18c3ff 100644
--- a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
+++ b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
@@ -33,20 +33,20 @@ export class BitwiseLogicOperationsPlugin extends FunctionPlugin {
   }
 
   public bitand(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITAND, (left: number, right: number) => {
-      return left & right
-    })
+    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITAND,
+      (left: number, right: number) => left & right
+    )
   }
 
   public bitor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITOR, (left: number, right: number) => {
-      return left | right
-    })
+    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITOR,
+      (left: number, right: number) => left | right
+    )
   }
 
   public bitxor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITXOR, (left: number, right: number) => {
-      return left ^ right
-    })
+    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITXOR,
+      (left: number, right: number) => left ^ right
+    )
   }
 }
diff --git a/src/interpreter/plugin/ErrorFunctionPlugin.ts b/src/interpreter/plugin/ErrorFunctionPlugin.ts
index 2ad9d40216..9ce3f6c85d 100644
--- a/src/interpreter/plugin/ErrorFunctionPlugin.ts
+++ b/src/interpreter/plugin/ErrorFunctionPlugin.ts
@@ -14,7 +14,7 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
       method: 'erf',
       parameters: [
         { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: EmptyValue as InternalScalarValue}, //hacking around since ERF can take 1 or 2 args
+        { argumentType: 'number', optionalArg: true},
       ],
     },
     'ERFC': {
@@ -27,10 +27,11 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
 
   public erf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.runFunction(ast.args, formulaAddress, ErrorFunctionPlugin.implementedFunctions.ERF, (lowerBound, upperBound) => {
-      if(ast.args.length === 1) {
+      if(upperBound===undefined) {
         return erf(lowerBound)
+      } else {
+        return erf(upperBound) - erf(lowerBound)
       }
-      return erf2(lowerBound, upperBound)
     })
   }
 
@@ -65,10 +66,6 @@ function erfApprox(x: number): number {
   return 1 - (1 / Math.pow(poly, polyExponent))
 }
 
-function erf2(lowerBound: number, upperBound: number): number {
-  return erf(upperBound) - erf(lowerBound)
-}
-
 function erfc(x: number): number {
   return 1 - erf(x)
 }
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 612ea79faf..d114c23cf2 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -40,7 +40,8 @@ export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerro
 export interface FunctionArgumentDefinition {
   argumentType: string,
   defaultValue?: InternalScalarValue,
-  softCoerce?: boolean,
+  softCoerce?: boolean, //failed coerce makes function ignore the arg instead of producing error
+  optionalArg?: boolean, //
   minValue?: number,
   maxValue?: number,
 }
@@ -96,35 +97,6 @@ export abstract class FunctionPlugin {
     return values
   }
 
-  protected validateTwoNumericArguments(ast: ProcedureAst, formulaAddress: SimpleCellAddress): [number, number] | CellError {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const left = this.evaluateAst(ast.args[0], formulaAddress)
-    if (left instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const coercedLeft = this.coerceScalarToNumberOrError(left)
-    if (coercedLeft instanceof CellError) {
-      return coercedLeft
-    }
-
-    const right = this.evaluateAst(ast.args[1], formulaAddress)
-    if (right instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const coercedRight = this.coerceScalarToNumberOrError(right)
-    if (coercedRight instanceof CellError) {
-      return coercedRight
-    }
-
-    return [coercedLeft, coercedRight]
-  }
-
   protected getNumericArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, position: number, min?: number, max?: number): number | CellError {
     if (position > ast.args.length - 1) {
       return new CellError(ErrorType.NA)
@@ -217,7 +189,14 @@ export abstract class FunctionPlugin {
       }
       const arg = scalarValues[i] ?? argumentDefinitions[j]?.defaultValue
       if(arg === undefined) {
-        return new CellError(ErrorType.NA)
+        if(argumentDefinitions[j]?.optionalArg) {
+          i++
+          j++
+          coercedArguments.push(undefined)
+          continue
+        } else {
+          return new CellError(ErrorType.NA)
+        }
       }
       const coercedArg = scalarValues[i] !== undefined ? this.coerceToType(arg, argumentDefinitions[j]) : arg
       if(coercedArg === undefined && !argumentDefinitions[j].softCoerce) {

From 82e0b1ebedd21f38c6b48001f51690d788a353e7 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Mon, 27 Jul 2020 12:41:00 +0200
Subject: [PATCH 53/97] .

---
 .../plugin/BitwiseLogicOperationsPlugin.ts    |   2 +-
 src/interpreter/plugin/CountUniquePlugin.ts   |   2 +-
 src/interpreter/plugin/DegreesPlugin.ts       |   6 +-
 src/interpreter/plugin/DeltaPlugin.ts         |  10 +-
 src/interpreter/plugin/ErrorFunctionPlugin.ts |   5 +-
 src/interpreter/plugin/FinancialPlugin.ts     |   5 +-
 src/interpreter/plugin/FunctionPlugin.ts      |  31 +--
 src/interpreter/plugin/IsEvenPlugin.ts        |  29 +--
 src/interpreter/plugin/IsOddPlugin.ts         |  28 +--
 src/interpreter/plugin/LogarithmPlugin.ts     |  19 +-
 src/interpreter/plugin/MathConstantsPlugin.ts |  28 +--
 .../plugin/RadixConversionPlugin.ts           | 220 +++++++-----------
 12 files changed, 142 insertions(+), 243 deletions(-)

diff --git a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
index c4bf18c3ff..0be06e94c1 100644
--- a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
+++ b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
@@ -3,7 +3,7 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
diff --git a/src/interpreter/plugin/CountUniquePlugin.ts b/src/interpreter/plugin/CountUniquePlugin.ts
index 8dac701166..32569ad9bb 100644
--- a/src/interpreter/plugin/CountUniquePlugin.ts
+++ b/src/interpreter/plugin/CountUniquePlugin.ts
@@ -4,7 +4,7 @@
  */
 
 import {CellError, EmptyValueType, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 /**
diff --git a/src/interpreter/plugin/DegreesPlugin.ts b/src/interpreter/plugin/DegreesPlugin.ts
index 8c93d2b8be..8a08df9d19 100644
--- a/src/interpreter/plugin/DegreesPlugin.ts
+++ b/src/interpreter/plugin/DegreesPlugin.ts
@@ -18,8 +18,8 @@ export class DegreesPlugin extends FunctionPlugin {
   }
 
   public degrees(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, DegreesPlugin.implementedFunctions.DEGREES, (arg) => {
-      return arg * (180 / Math.PI)
-    })
+    return this.runFunction(ast.args, formulaAddress, DegreesPlugin.implementedFunctions.DEGREES,
+      (arg) => arg * (180 / Math.PI)
+    )
   }
 }
diff --git a/src/interpreter/plugin/DeltaPlugin.ts b/src/interpreter/plugin/DeltaPlugin.ts
index 6cfbf84f95..631f280c4f 100644
--- a/src/interpreter/plugin/DeltaPlugin.ts
+++ b/src/interpreter/plugin/DeltaPlugin.ts
@@ -3,8 +3,8 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 export class DeltaPlugin extends FunctionPlugin {
@@ -19,8 +19,8 @@ export class DeltaPlugin extends FunctionPlugin {
   }
 
   public delta(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, DeltaPlugin.implementedFunctions.DELTA, (left: number, right: number) => {
-      return left === right ? 1 : 0
-    })
+    return this.runFunction(ast.args, formulaAddress, DeltaPlugin.implementedFunctions.DELTA,
+      (left: number, right: number) => (left === right ? 1 : 0)
+    )
   }
 }
diff --git a/src/interpreter/plugin/ErrorFunctionPlugin.ts b/src/interpreter/plugin/ErrorFunctionPlugin.ts
index 9ce3f6c85d..1afbdb682c 100644
--- a/src/interpreter/plugin/ErrorFunctionPlugin.ts
+++ b/src/interpreter/plugin/ErrorFunctionPlugin.ts
@@ -3,9 +3,8 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, EmptyValue, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {upperBound} from '../../ColumnSearch/ColumnIndex'
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 export class ErrorFunctionPlugin extends FunctionPlugin {
diff --git a/src/interpreter/plugin/FinancialPlugin.ts b/src/interpreter/plugin/FinancialPlugin.ts
index e6a26620d7..1c904b3ef7 100644
--- a/src/interpreter/plugin/FinancialPlugin.ts
+++ b/src/interpreter/plugin/FinancialPlugin.ts
@@ -3,9 +3,8 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {SimpleRangeValue} from '../InterpreterValue'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 export class FinancialPlugin extends FunctionPlugin {
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index d114c23cf2..3601e0633e 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -10,7 +10,7 @@ import {ColumnSearchStrategy} from '../../ColumnSearch/ColumnSearchStrategy'
 import {Config} from '../../Config'
 import {DependencyGraph} from '../../DependencyGraph'
 import {Maybe} from '../../Maybe'
-import {Ast, AstNodeType, ProcedureAst} from '../../parser'
+import {Ast, ProcedureAst} from '../../parser'
 import {coerceScalarToBoolean, coerceScalarToString} from '../ArithmeticHelper'
 import {Interpreter} from '../Interpreter'
 import {InterpreterValue, SimpleRangeValue} from '../InterpreterValue'
@@ -44,6 +44,8 @@ export interface FunctionArgumentDefinition {
   optionalArg?: boolean, //
   minValue?: number,
   maxValue?: number,
+  lessThan?: number,
+  greaterThan?: number,
 }
 
 export type PluginFunctionType = (ast: ProcedureAst, formulaAddress: SimpleCellAddress) => InternalScalarValue
@@ -97,27 +99,6 @@ export abstract class FunctionPlugin {
     return values
   }
 
-  protected getNumericArgument(ast: ProcedureAst, formulaAddress: SimpleCellAddress, position: number, min?: number, max?: number): number | CellError {
-    if (position > ast.args.length - 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args[position].type === AstNodeType.EMPTY) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = this.evaluateAst(ast.args[position]!, formulaAddress)
-
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const value = this.coerceScalarToNumberOrError(arg)
-    if (typeof value === 'number' && min !== undefined && max !== undefined && (value < min || value > max)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    return value
-  }
-
   public coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
   public coerceToType(arg: InterpreterValue, coercedType: FunctionArgumentDefinition): Maybe<InterpreterValue> {
@@ -142,6 +123,12 @@ export abstract class FunctionPlugin {
           if (coercedType.minValue !== undefined && value < coercedType.minValue) {
             return new CellError(ErrorType.NUM)
           }
+          if(coercedType.lessThan !== undefined && value >= coercedType.lessThan) {
+            return new CellError(ErrorType.NUM)
+          }
+          if (coercedType.greaterThan !== undefined && value <= coercedType.greaterThan) {
+            return new CellError(ErrorType.NUM)
+          }
           if(coercedType.argumentType === 'integer' && !Number.isInteger(value)) {
             return new CellError(ErrorType.NUM)
           }
diff --git a/src/interpreter/plugin/IsEvenPlugin.ts b/src/interpreter/plugin/IsEvenPlugin.ts
index 0a12b424d9..37bfd85cc5 100644
--- a/src/interpreter/plugin/IsEvenPlugin.ts
+++ b/src/interpreter/plugin/IsEvenPlugin.ts
@@ -3,36 +3,23 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {SimpleRangeValue} from '../InterpreterValue'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 export class IsEvenPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISEVEN': {
       method: 'iseven',
+      parameters: [
+        { argumentType: 'number'}
+      ]
     },
   }
 
   public iseven(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length != 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const coercedValue = this.coerceScalarToNumberOrError(arg)
-    if (coercedValue instanceof CellError) {
-      return coercedValue
-    } else {
-      return (coercedValue % 2 === 0)
-    }
-
+    return this.runFunction(ast.args, formulaAddress, IsEvenPlugin.implementedFunctions.ISEVEN,
+      (val) => (val % 2 === 0)
+    )
   }
 }
diff --git a/src/interpreter/plugin/IsOddPlugin.ts b/src/interpreter/plugin/IsOddPlugin.ts
index 6d45b4ff00..b83e621d02 100644
--- a/src/interpreter/plugin/IsOddPlugin.ts
+++ b/src/interpreter/plugin/IsOddPlugin.ts
@@ -3,35 +3,23 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {SimpleRangeValue} from '../InterpreterValue'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 export class IsOddPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISODD': {
       method: 'isodd',
+      parameters: [
+        { argumentType: 'number'}
+      ]
     },
   }
 
   public isodd(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length != 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const coercedValue = this.coerceScalarToNumberOrError(arg)
-    if (coercedValue instanceof CellError) {
-      return coercedValue
-    } else {
-      return (coercedValue % 2 === 1)
-    }
+    return this.runFunction(ast.args, formulaAddress, IsOddPlugin.implementedFunctions.ISODD,
+      (val) => (val % 2 === 1)
+    )
   }
 }
diff --git a/src/interpreter/plugin/LogarithmPlugin.ts b/src/interpreter/plugin/LogarithmPlugin.ts
index ab44a05863..0884a1128c 100644
--- a/src/interpreter/plugin/LogarithmPlugin.ts
+++ b/src/interpreter/plugin/LogarithmPlugin.ts
@@ -3,9 +3,8 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {SimpleRangeValue} from '../InterpreterValue'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 export class LogarithmPlugin extends FunctionPlugin {
@@ -20,8 +19,8 @@ export class LogarithmPlugin extends FunctionPlugin {
     'LOG': {
       method: 'log',
       parameters: [
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 10 },
+        { argumentType: 'number', greaterThan: 0 },
+        { argumentType: 'number', defaultValue: 10, greaterThan: 0 },
       ],
     },
     'LN': {
@@ -37,13 +36,9 @@ export class LogarithmPlugin extends FunctionPlugin {
   }
 
   public log(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LOG, (arg: number, base: number) => {
-        if(arg > 0 && base > 0) {
-          return Math.log(arg) / Math.log(base)
-        } else {
-          return new CellError(ErrorType.NUM)
-        }
-      })
+    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LOG,
+      (arg: number, base: number) => Math.log(arg) / Math.log(base)
+    )
   }
 
   public ln(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
diff --git a/src/interpreter/plugin/MathConstantsPlugin.ts b/src/interpreter/plugin/MathConstantsPlugin.ts
index 80e1bfc9b9..bafc1a460b 100644
--- a/src/interpreter/plugin/MathConstantsPlugin.ts
+++ b/src/interpreter/plugin/MathConstantsPlugin.ts
@@ -3,8 +3,8 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 const PI = parseFloat(Math.PI.toFixed(14))
@@ -14,31 +14,23 @@ export class MathConstantsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'PI': {
       method: 'pi',
+      parameters: [],
     },
     'E': {
       method: 'e',
+      parameters: [],
     },
   }
 
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public pi(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length > 0) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    return PI
+    return this.runFunction(ast.args, formulaAddress, MathConstantsPlugin.implementedFunctions.PI,
+      () => PI
+    )
   }
 
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public e(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length > 0) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    return E
+    return this.runFunction(ast.args, formulaAddress, MathConstantsPlugin.implementedFunctions.E,
+      () => E
+    )
   }
 }
diff --git a/src/interpreter/plugin/RadixConversionPlugin.ts b/src/interpreter/plugin/RadixConversionPlugin.ts
index ad5fd62663..7ddb7075ff 100644
--- a/src/interpreter/plugin/RadixConversionPlugin.ts
+++ b/src/interpreter/plugin/RadixConversionPlugin.ts
@@ -5,9 +5,8 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {padLeft} from '../../format/format'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {coerceScalarToString} from '../ArithmeticHelper'
-import {SimpleRangeValue} from '../InterpreterValue'
+import {Maybe} from '../../Maybe'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 const NUMBER_OF_BITS = 10
@@ -20,187 +19,132 @@ export class RadixConversionPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DEC2BIN': {
       method: 'dec2bin',
+      parameters: [
+        { argumentType: 'number', minValue: minValFromBase(2), maxValue: maxValFromBase(2) },
+        { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
+      ],
     },
     'DEC2OCT': {
       method: 'dec2oct',
+      parameters: [
+        { argumentType: 'number', minValue: minValFromBase(8), maxValue: maxValFromBase(8) },
+        { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
+      ],
     },
     'DEC2HEX': {
       method: 'dec2hex',
+      parameters: [
+        { argumentType: 'number', minValue: minValFromBase(16), maxValue: maxValFromBase(16) },
+        { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
+      ],
     },
     'BIN2DEC': {
       method: 'bin2dec',
+      parameters: [
+        { argumentType: 'string' }
+      ],
     },
     'BIN2OCT': {
       method: 'bin2oct',
+      parameters: [
+        { argumentType: 'string' },
+        { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
+      ],
     },
     'BIN2HEX': {
       method: 'bin2hex',
+      parameters: [
+        { argumentType: 'string' },
+        { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
+      ],
     },
     'DECIMAL': {
       method: 'decimal',
+      parameters: [
+        { argumentType: 'string' },
+        { argumentType: 'number', minValue: MIN_BASE, maxValue: MAX_BASE },
+      ],
     },
     'BASE': {
       method: 'base',
+      parameters: [
+        { argumentType: 'number', minValue: 0 },
+        { argumentType: 'number', minValue: MIN_BASE, maxValue: MAX_BASE },
+        { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
+      ],
     },
   }
 
   public dec2bin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.dec2base(ast, formulaAddress, 2)
+    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.DEC2BIN,
+      (value, places) => decimalToBaseWithExactPadding(value, 2, places)
+    )
   }
 
   public dec2oct(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.dec2base(ast, formulaAddress, 8)
+    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.DEC2OCT,
+      (value, places) => decimalToBaseWithExactPadding(value, 8, places)
+    )
   }
 
   public dec2hex(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.dec2base(ast, formulaAddress, 16)
+    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.DEC2HEX,
+      (value, places) => decimalToBaseWithExactPadding(value, 16, places)
+    )
   }
 
   public bin2dec(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 1) {
-      return new CellError(ErrorType.NA)
-    }
-
-    const binaryWithSign = this.getFirstArgumentAsNumberInBase(ast, formulaAddress, 2, NUMBER_OF_BITS)
-    if (binaryWithSign instanceof CellError) {
-      return binaryWithSign
-    }
-
-    return twoComplementToDecimal(binaryWithSign)
+    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.BIN2DEC, (binary) => {
+        const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
+        if(binaryWithSign === undefined) {
+          return new CellError(ErrorType.NUM)
+        }
+        return twoComplementToDecimal(binaryWithSign)
+      })
   }
 
   public bin2oct(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.bin2base(ast, formulaAddress, 8)
+    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.BIN2OCT, (binary, places) => {
+      const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
+      if(binaryWithSign === undefined) {
+        return new CellError(ErrorType.NUM)
+      }
+      return decimalToBaseWithExactPadding(twoComplementToDecimal(binaryWithSign), 8, places)
+    })
   }
 
   public bin2hex(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.bin2base(ast, formulaAddress, 16)
+    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.BIN2HEX, (binary, places) => {
+      const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
+      if(binaryWithSign === undefined) {
+        return new CellError(ErrorType.NUM)
+      }
+      return decimalToBaseWithExactPadding(twoComplementToDecimal(binaryWithSign), 16, places)
+    })
   }
 
   public base(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length < 2 || ast.args.length > 3) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const value = this.getNumericArgument(ast, formulaAddress, 0)
-    if (value instanceof CellError) {
-      return value
-    }
-
-    const base = this.getNumericArgument(ast, formulaAddress, 1, MIN_BASE, MAX_BASE)
-    if (base instanceof CellError) {
-      return base
-    }
-
-    let padding
-    if (ast.args.length === 3) {
-      padding = this.getNumericArgument(ast, formulaAddress, 2, 0, DECIMAL_NUMBER_OF_BITS)
-      if (padding instanceof CellError) {
-        return padding
-      }
-    }
-
-    if (value < 0) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    return decimalToBaseWithMinimumPadding(value, base, padding)
+    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.BASE, decimalToBaseWithMinimumPadding)
   }
 
   public decimal(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const base = this.getNumericArgument(ast, formulaAddress, 1, MIN_BASE, MAX_BASE)
-    if (base instanceof CellError) {
-      return base
-    }
-
-    const input = this.getFirstArgumentAsNumberInBase(ast, formulaAddress, base, DECIMAL_NUMBER_OF_BITS)
-    if (input instanceof CellError) {
-      return input
-    }
-
-    return parseInt(input, base)
-  }
-
-  private bin2base(ast: ProcedureAst, formulaAddress: SimpleCellAddress, base: number): InternalScalarValue {
-    if (ast.args.length < 1 || ast.args.length > 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const binaryWithSign = this.getFirstArgumentAsNumberInBase(ast, formulaAddress, 2, NUMBER_OF_BITS)
-    if (binaryWithSign instanceof CellError) {
-      return binaryWithSign
-    }
-
-    let places
-    if (ast.args.length === 2) {
-      places = this.getNumericArgument(ast, formulaAddress, 1, 1, 10)
-      if (places instanceof CellError) {
-        return places
-      }
-    }
-
-    const decimal = twoComplementToDecimal(binaryWithSign)
-    return decimalToBaseWithExactPadding(decimal, base, places)
-  }
-
-  private dec2base(ast: ProcedureAst, formulaAddress: SimpleCellAddress, base: number): InternalScalarValue {
-    if (ast.args.length < 1 || ast.args.length > 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    let places
-    if (ast.args.length === 2) {
-      places = this.getNumericArgument(ast, formulaAddress, 1, 1, 10)
-      if (places instanceof CellError) {
-        return places
-      }
-    }
-
-    const min = -Math.pow(base, NUMBER_OF_BITS) / 2
-    const max = -min - 1
-
-    const value = this.getNumericArgument(ast, formulaAddress, 0, min, max)
-    if (value instanceof CellError) {
-      return value
-    }
-
-    return decimalToBaseWithExactPadding(value, base, places)
-  }
-
-  private getFirstArgumentAsNumberInBase(ast: ProcedureAst, formulaAddress: SimpleCellAddress, base: number, maxLength: number): string | CellError {
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const value = coerceScalarToString(arg)
-    if (typeof value === 'string') {
-      const baseAlphabet = ALPHABET.substr(0, base)
-      const regex = new RegExp(`^[${baseAlphabet}]+$`)
-      if (value.length > maxLength || !regex.test(value)) {
+    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.DECIMAL, (arg, base) => {
+      const input = coerceStringToBase(arg, base, DECIMAL_NUMBER_OF_BITS)
+      if(input === undefined) {
         return new CellError(ErrorType.NUM)
       }
-    }
+      return parseInt(input, base)
+    })
+  }
+}
 
-    return value
+function coerceStringToBase(value: string, base: number, maxLength: number): Maybe<string> {
+  const baseAlphabet = ALPHABET.substr(0, base)
+  const regex = new RegExp(`^[${baseAlphabet}]+$`)
+  if (value.length > maxLength || !regex.test(value)) {
+    return undefined
   }
+  return value
 }
 
 function decimalToBaseWithExactPadding(value: number, base: number, places?: number): string | CellError {
@@ -214,6 +158,14 @@ function decimalToBaseWithExactPadding(value: number, base: number, places?: num
   }
 }
 
+function minValFromBase(base: number) {
+  return -Math.pow(base, NUMBER_OF_BITS) / 2
+}
+
+function maxValFromBase(base: number) {
+  return -minValFromBase(base) - 1
+}
+
 function decimalToBaseWithMinimumPadding(value: number, base: number, places?: number): string {
   const result = decimalToRadixComplement(value, base)
   if (places !== undefined && places > result.length) {

From e6d92a547ee81c2b035481b30c6053bd26b1be48 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Mon, 27 Jul 2020 14:40:13 +0200
Subject: [PATCH 54/97] repeated args fixed

---
 src/interpreter/plugin/BooleanPlugin.ts  | 60 +++++++-----------------
 src/interpreter/plugin/FunctionPlugin.ts | 24 ++++++----
 test/interpreter/function-and.spec.ts    | 18 +++++--
 test/interpreter/function-or.spec.ts     | 17 ++++++-
 test/interpreter/function-xor.spec.ts    | 17 ++++++-
 5 files changed, 77 insertions(+), 59 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index d33771e1f6..eabcc405d9 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -33,7 +33,7 @@ export class BooleanPlugin extends FunctionPlugin {
     'AND': {
       method: 'and',
       parameters: [
-        { argumentType: 'boolean', softCoerce: true },
+        { argumentType: 'boolean' },
       ],
       repeatedArg: true,
       expandRanges: true,
@@ -41,7 +41,7 @@ export class BooleanPlugin extends FunctionPlugin {
     'OR': {
       method: 'or',
       parameters: [
-        { argumentType: 'boolean', softCoerce: true },
+        { argumentType: 'boolean' },
       ],
       repeatedArg: true,
       expandRanges: true,
@@ -49,7 +49,7 @@ export class BooleanPlugin extends FunctionPlugin {
     'XOR': {
       method: 'xor',
       parameters: [
-        { argumentType: 'boolean', softCoerce: true },
+        { argumentType: 'boolean' },
       ],
       repeatedArg: true,
       expandRanges: true,
@@ -127,11 +127,7 @@ export class BooleanPlugin extends FunctionPlugin {
    */
   public conditionalIf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InterpreterValue {
     return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IF, (condition, arg2, arg3) => {
-      if(condition===undefined) {
-        return new CellError(ErrorType.VALUE)
-      } else {
         return condition ? arg2 : arg3
-      }
     })
   }
 
@@ -144,15 +140,9 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public and(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND, (...args) => {
-      if(args.some((arg: Maybe<InternalScalarValue>) => arg===false)) {
-        return false
-      } else if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
-        return true
-      } else {
-        return new CellError(ErrorType.VALUE)
-      }
-    })
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND,
+      (...args) => !args.some( (arg:boolean) => !arg)
+    )
   }
 
   /**
@@ -164,40 +154,24 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public or(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR, (...args) => {
-      if(args.some((arg: Maybe<InternalScalarValue>) => arg===true)) {
-        return true
-      } else if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
-        return false
-      } else {
-        return new CellError(ErrorType.VALUE)
-      }
-    })
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR,
+      (...args) => args.some( (arg:boolean) => arg)
+    )
   }
 
   public not(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.NOT, (arg) => {
-      if(arg===undefined) {
-        return new CellError(ErrorType.VALUE)
-      } else {
-        return !arg
-      }
-    })
+    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.NOT, (arg) => !arg)
   }
 
   public xor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.XOR, (...args) => {
-      if(args.some((arg: Maybe<InternalScalarValue>) => arg!==undefined)) {
-        let cnt = 0
-        args.forEach((arg: Maybe<InternalScalarValue>) => {
-          if( arg===true ) {
-            cnt++
-          }
-        })
-        return (cnt%2) === 1
-      } else {
-        return new CellError(ErrorType.VALUE)
-      }
+      let cnt = 0
+      args.forEach((arg: boolean) => {
+        if( arg ) {
+          cnt++
+        }
+      })
+      return (cnt%2) === 1
     })
   }
 
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 3601e0633e..86237a9392 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -76,15 +76,15 @@ export abstract class FunctionPlugin {
     return this.interpreter.evaluateAst(ast, formulaAddress)
   }
 
-  protected* iterateOverScalarValues(asts: Ast[], formulaAddress: SimpleCellAddress): IterableIterator<InternalScalarValue> {
+  protected* iterateOverScalarValues(asts: Ast[], formulaAddress: SimpleCellAddress): IterableIterator<[InternalScalarValue,boolean]> {
     for (const argAst of asts) {
       const value = this.evaluateAst(argAst, formulaAddress)
       if (value instanceof SimpleRangeValue) {
         for (const scalarValue of value.valuesFromTopLeftCorner()) {
-          yield scalarValue
+          yield [scalarValue, true]
         }
       } else {
-        yield value
+        yield [value, false]
       }
     }
   }
@@ -155,11 +155,11 @@ export abstract class FunctionPlugin {
   ) => {
     const argumentDefinitions: FunctionArgumentDefinition[] = functionDefinition.parameters!
     assert(argumentDefinitions !== undefined)
-    let scalarValues: InterpreterValue[]
+    let scalarValues: [InterpreterValue, boolean][]
     if(functionDefinition.expandRanges) {
       scalarValues = [...this.iterateOverScalarValues(args, formulaAddress)]
     } else {
-      scalarValues = args.map((ast) => this.evaluateAst(ast, formulaAddress))
+      scalarValues = args.map((ast) => [this.evaluateAst(ast, formulaAddress), false])
     }
     const coercedArguments: Maybe<InterpreterValue>[] = []
 
@@ -174,7 +174,8 @@ export abstract class FunctionPlugin {
           return new CellError(ErrorType.NA)
         }
       }
-      const arg = scalarValues[i] ?? argumentDefinitions[j]?.defaultValue
+      const [val,ignorable] = scalarValues[i] ?? [undefined, undefined]
+      const arg = val ?? argumentDefinitions[j]?.defaultValue
       if(arg === undefined) {
         if(argumentDefinitions[j]?.optionalArg) {
           i++
@@ -185,9 +186,14 @@ export abstract class FunctionPlugin {
           return new CellError(ErrorType.NA)
         }
       }
-      const coercedArg = scalarValues[i] !== undefined ? this.coerceToType(arg, argumentDefinitions[j]) : arg
-      if(coercedArg === undefined && !argumentDefinitions[j].softCoerce) {
-        argCoerceFailure = argCoerceFailure ?? (new CellError(ErrorType.VALUE))
+      const coercedArg = val !== undefined ? this.coerceToType(arg, argumentDefinitions[j]) : arg
+      if(coercedArg === undefined) {
+        if(!ignorable) {
+          argCoerceFailure = argCoerceFailure ?? (new CellError(ErrorType.VALUE))
+        }
+        i++
+        j++
+        continue
       }
       if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
         argCoerceFailure = argCoerceFailure ?? coercedArg
diff --git a/test/interpreter/function-and.spec.ts b/test/interpreter/function-and.spec.ts
index 2958f16db3..64444770cb 100644
--- a/test/interpreter/function-and.spec.ts
+++ b/test/interpreter/function-and.spec.ts
@@ -1,5 +1,4 @@
-import {HyperFormula} from '../../src'
-import {ErrorType} from '../../src/Cell'
+import {ErrorType, HyperFormula} from '../../src'
 import {adr, detailedError} from '../testUtils'
 
 describe('Function AND', () => {
@@ -22,14 +21,27 @@ describe('Function AND', () => {
     expect(engine.getCellValue(adr('C1'))).toBe(true)
   })
 
-  it('use coercion', () => {
+  it('use coercion #1', () => {
     const engine = HyperFormula.buildFromArray([
       ['=AND("TRUE", 1)'],
       ['=AND("foo", TRUE())'],
     ])
 
+    expect(engine.getCellValue(adr('A1'))).toBe(true)
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('use coercion #2', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=AND(A4:B4)'],
+      ['=AND(C4:D4)'],
+      ['=AND(C4:D4, "foo")'],
+      ["TRUE", 1, "foo", "=TRUE()"],
+    ])
+
     expect(engine.getCellValue(adr('A1'))).toBe(true)
     expect(engine.getCellValue(adr('A2'))).toBe(true)
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.VALUE))
   })
 
   it('if error in range found, returns first one in row-by-row order', () => {
diff --git a/test/interpreter/function-or.spec.ts b/test/interpreter/function-or.spec.ts
index cff8d05a15..6b0f6fcce0 100644
--- a/test/interpreter/function-or.spec.ts
+++ b/test/interpreter/function-or.spec.ts
@@ -14,14 +14,27 @@ describe('Function OR', () => {
     expect(engine.getCellValue(adr('D1'))).toEqual(detailedError(ErrorType.VALUE))
   })
 
-  it('use coercion', () => {
+  it('use coercion #1', () => {
     const engine = HyperFormula.buildFromArray([
       ['=OR("TRUE", 0)'],
       ['=OR("foo", 0)'],
     ])
 
     expect(engine.getCellValue(adr('A1'))).toBe(true)
-    expect(engine.getCellValue(adr('A2'))).toBe(false)
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('use coercion #2', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=OR(A4:B4)'],
+      ['=OR(C4:D4)'],
+      ['=OR(C4:D4, "foo")'],
+      ["TRUE", 1, "foo", "=TRUE()"],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toBe(true)
+    expect(engine.getCellValue(adr('A2'))).toBe(true)
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.VALUE))
   })
 
   it('function OR with numerical arguments', () => {
diff --git a/test/interpreter/function-xor.spec.ts b/test/interpreter/function-xor.spec.ts
index ff377ff095..561f9b1fdc 100644
--- a/test/interpreter/function-xor.spec.ts
+++ b/test/interpreter/function-xor.spec.ts
@@ -35,7 +35,7 @@ describe('Function XOR', () => {
     expect(engine.getCellValue(adr('A2'))).toBe(false)
   })
 
-  it('use coercion', () => {
+  it('use coercion #1', () => {
     const engine = HyperFormula.buildFromArray([
       ['=XOR("TRUE")'],
       ['=XOR(1)'],
@@ -44,7 +44,20 @@ describe('Function XOR', () => {
 
     expect(engine.getCellValue(adr('A1'))).toBe(true)
     expect(engine.getCellValue(adr('A2'))).toBe(true)
-    expect(engine.getCellValue(adr('A3'))).toBe(true)
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('use coercion #2', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=XOR(A4:B4)'],
+      ['=XOR(C4:D4)'],
+      ['=XOR(C4:D4, "foo")'],
+      ["TRUE", 1, "foo", "=TRUE()"],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toBe(false)
+    expect(engine.getCellValue(adr('A2'))).toBe(true)
+    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.VALUE))
   })
 
   it('when no coercible to number arguments', () => {

From 314732dd968b4b6ad92760d276c6aa7b77c0544a Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Mon, 27 Jul 2020 14:42:39 +0200
Subject: [PATCH 55/97] linter

---
 src/interpreter/plugin/BooleanPlugin.ts  | 4 ++--
 src/interpreter/plugin/FunctionPlugin.ts | 4 ++--
 test/interpreter/function-and.spec.ts    | 2 +-
 test/interpreter/function-or.spec.ts     | 2 +-
 test/interpreter/function-xor.spec.ts    | 2 +-
 5 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index eabcc405d9..2e57257f14 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -141,7 +141,7 @@ export class BooleanPlugin extends FunctionPlugin {
    */
   public and(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND,
-      (...args) => !args.some( (arg:boolean) => !arg)
+      (...args) => !args.some( (arg: boolean) => !arg)
     )
   }
 
@@ -155,7 +155,7 @@ export class BooleanPlugin extends FunctionPlugin {
    */
   public or(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR,
-      (...args) => args.some( (arg:boolean) => arg)
+      (...args) => args.some( (arg: boolean) => arg)
     )
   }
 
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 86237a9392..be5d68d692 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -76,7 +76,7 @@ export abstract class FunctionPlugin {
     return this.interpreter.evaluateAst(ast, formulaAddress)
   }
 
-  protected* iterateOverScalarValues(asts: Ast[], formulaAddress: SimpleCellAddress): IterableIterator<[InternalScalarValue,boolean]> {
+  protected* iterateOverScalarValues(asts: Ast[], formulaAddress: SimpleCellAddress): IterableIterator<[InternalScalarValue, boolean]> {
     for (const argAst of asts) {
       const value = this.evaluateAst(argAst, formulaAddress)
       if (value instanceof SimpleRangeValue) {
@@ -174,7 +174,7 @@ export abstract class FunctionPlugin {
           return new CellError(ErrorType.NA)
         }
       }
-      const [val,ignorable] = scalarValues[i] ?? [undefined, undefined]
+      const [val, ignorable] = scalarValues[i] ?? [undefined, undefined]
       const arg = val ?? argumentDefinitions[j]?.defaultValue
       if(arg === undefined) {
         if(argumentDefinitions[j]?.optionalArg) {
diff --git a/test/interpreter/function-and.spec.ts b/test/interpreter/function-and.spec.ts
index 64444770cb..092fb56750 100644
--- a/test/interpreter/function-and.spec.ts
+++ b/test/interpreter/function-and.spec.ts
@@ -36,7 +36,7 @@ describe('Function AND', () => {
       ['=AND(A4:B4)'],
       ['=AND(C4:D4)'],
       ['=AND(C4:D4, "foo")'],
-      ["TRUE", 1, "foo", "=TRUE()"],
+      ['TRUE', 1, 'foo', '=TRUE()'],
     ])
 
     expect(engine.getCellValue(adr('A1'))).toBe(true)
diff --git a/test/interpreter/function-or.spec.ts b/test/interpreter/function-or.spec.ts
index 6b0f6fcce0..cf0ec51b1d 100644
--- a/test/interpreter/function-or.spec.ts
+++ b/test/interpreter/function-or.spec.ts
@@ -29,7 +29,7 @@ describe('Function OR', () => {
       ['=OR(A4:B4)'],
       ['=OR(C4:D4)'],
       ['=OR(C4:D4, "foo")'],
-      ["TRUE", 1, "foo", "=TRUE()"],
+      ['TRUE', 1, 'foo', '=TRUE()'],
     ])
 
     expect(engine.getCellValue(adr('A1'))).toBe(true)
diff --git a/test/interpreter/function-xor.spec.ts b/test/interpreter/function-xor.spec.ts
index 561f9b1fdc..4cdfb88c37 100644
--- a/test/interpreter/function-xor.spec.ts
+++ b/test/interpreter/function-xor.spec.ts
@@ -52,7 +52,7 @@ describe('Function XOR', () => {
       ['=XOR(A4:B4)'],
       ['=XOR(C4:D4)'],
       ['=XOR(C4:D4, "foo")'],
-      ["TRUE", 1, "foo", "=TRUE()"],
+      ['TRUE', 1, 'foo', '=TRUE()'],
     ])
 
     expect(engine.getCellValue(adr('A1'))).toBe(false)

From e09d9f4b8d30b4fecffcc38d5a3e51bf674cc090 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Mon, 27 Jul 2020 14:47:28 +0200
Subject: [PATCH 56/97] linter

---
 src/interpreter/plugin/BooleanPlugin.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index 2e57257f14..4b545137e2 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -4,7 +4,6 @@
  */
 
 import {CellError, ErrorType, InternalNoErrorCellValue, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {Maybe} from '../../Maybe'
 import {ProcedureAst} from '../../parser'
 import {InterpreterValue} from '../InterpreterValue'
 import {FunctionPlugin} from './FunctionPlugin'

From 6648d72285564437a7fe8c1cec6506d450c13fe1 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Mon, 27 Jul 2020 15:24:10 +0200
Subject: [PATCH 57/97] .

---
 src/interpreter/plugin/RandomPlugin.ts   | 11 ++---------
 src/interpreter/plugin/RoundingPlugin.ts |  5 +----
 src/interpreter/plugin/SqrtPlugin.ts     |  2 +-
 src/interpreter/plugin/TextPlugin.ts     |  3 +--
 4 files changed, 5 insertions(+), 16 deletions(-)

diff --git a/src/interpreter/plugin/RandomPlugin.ts b/src/interpreter/plugin/RandomPlugin.ts
index ad87065123..f85a65c562 100644
--- a/src/interpreter/plugin/RandomPlugin.ts
+++ b/src/interpreter/plugin/RandomPlugin.ts
@@ -11,6 +11,7 @@ export class RandomPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'RAND': {
       method: 'rand',
+      parameters: [],
       isVolatile: true,
     },
   }
@@ -24,15 +25,7 @@ export class RandomPlugin extends FunctionPlugin {
    * @param ast
    * @param formulaAddress
    */
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   public rand(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 0) {
-      return new CellError(ErrorType.NA)
-    }
-
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-    return Math.random()
+    return this.runFunction(ast.args, formulaAddress, RandomPlugin.implementedFunctions.RAND, Math.random)
   }
 }
diff --git a/src/interpreter/plugin/RoundingPlugin.ts b/src/interpreter/plugin/RoundingPlugin.ts
index 18eba40037..b714c2c6f0 100644
--- a/src/interpreter/plugin/RoundingPlugin.ts
+++ b/src/interpreter/plugin/RoundingPlugin.ts
@@ -4,12 +4,9 @@
  */
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {SimpleRangeValue} from '../InterpreterValue'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
-type RoundingFunction = (numberToRound: number, places: number) => number
-
 export function findNextOddNumber(arg: number): number {
   const ceiled = Math.ceil(arg)
   return (ceiled % 2 === 1) ? ceiled : ceiled + 1
diff --git a/src/interpreter/plugin/SqrtPlugin.ts b/src/interpreter/plugin/SqrtPlugin.ts
index 93734de57b..7ca2c1ab4b 100644
--- a/src/interpreter/plugin/SqrtPlugin.ts
+++ b/src/interpreter/plugin/SqrtPlugin.ts
@@ -3,7 +3,7 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 7db5dd3c38..fb6588beaf 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -4,8 +4,7 @@
  */
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
-import {coerceScalarToString} from '../ArithmeticHelper'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 /**

From 4643f2c48f33ff3dfd32bd083b7d61e6eb7f87bb Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Mon, 27 Jul 2020 16:21:37 +0200
Subject: [PATCH 58/97] this.parameter helper method

---
 src/index.ts                                  |   4 +-
 src/interpreter/index.ts                      |   4 +-
 src/interpreter/plugin/AbsPlugin.ts           |   6 +-
 src/interpreter/plugin/BitShiftPlugin.ts      |  12 +-
 .../plugin/BitwiseLogicOperationsPlugin.ts    |  18 +--
 src/interpreter/plugin/BooleanPlugin.ts       | 150 ++++++++++--------
 src/interpreter/plugin/CharPlugin.ts          |  10 +-
 src/interpreter/plugin/CodePlugin.ts          |  10 +-
 src/interpreter/plugin/CountUniquePlugin.ts   |  16 +-
 src/interpreter/plugin/DegreesPlugin.ts       |  10 +-
 src/interpreter/plugin/DeltaPlugin.ts         |  12 +-
 src/interpreter/plugin/ErrorFunctionPlugin.ts |  24 +--
 src/interpreter/plugin/ExpPlugin.ts           |   6 +-
 src/interpreter/plugin/FinancialPlugin.ts     |  84 +++++-----
 src/interpreter/plugin/FunctionPlugin.ts      |  36 +++--
 src/interpreter/plugin/InformationPlugin.ts   |  36 ++---
 src/interpreter/plugin/IsEvenPlugin.ts        |   6 +-
 src/interpreter/plugin/IsOddPlugin.ts         |  10 +-
 src/interpreter/plugin/LogarithmPlugin.ts     |  32 ++--
 src/interpreter/plugin/MathConstantsPlugin.ts |   8 +-
 src/interpreter/plugin/MedianPlugin.ts        |  14 +-
 src/interpreter/plugin/ModuloPlugin.ts        |   6 +-
 src/interpreter/plugin/PowerPlugin.ts         |   6 +-
 src/interpreter/plugin/RadiansPlugin.ts       |   6 +-
 .../plugin/RadixConversionPlugin.ts           |  48 +++---
 src/interpreter/plugin/RandomPlugin.ts        |   8 +-
 src/interpreter/plugin/RoundingPlugin.ts      |  46 +++---
 src/interpreter/plugin/SqrtPlugin.ts          |   6 +-
 src/interpreter/plugin/TextPlugin.ts          | 130 ++++++++-------
 src/interpreter/plugin/TrigonometryPlugin.ts  |  48 +++---
 30 files changed, 444 insertions(+), 368 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index abf206947b..0ad80e9f41 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -50,7 +50,7 @@ import {
   UnableToParseError
 } from './errors'
 import * as plugins from './interpreter/plugin'
-import {FunctionArgumentDefinition, FunctionPlugin, FunctionPluginDefinition} from './interpreter'
+import {FunctionArgument, FunctionPlugin, FunctionPluginDefinition} from './interpreter'
 import {ColumnRowIndex} from './CrudOperations'
 
 /** @internal */
@@ -121,7 +121,7 @@ export {
   ColumnRowIndex,
   RawTranslationPackage,
   FunctionPluginDefinition,
-  FunctionArgumentDefinition,
+  FunctionArgument,
   NamedExpression,
   NamedExpressionOptions,
   HyperFormula,
diff --git a/src/interpreter/index.ts b/src/interpreter/index.ts
index bfd9c517a9..3d66ea98d2 100644
--- a/src/interpreter/index.ts
+++ b/src/interpreter/index.ts
@@ -4,7 +4,7 @@
  */
 
 import {
-  FunctionArgumentDefinition,
+  FunctionArgument,
   FunctionMetadata,
   FunctionPlugin,
   FunctionPluginDefinition,
@@ -14,7 +14,7 @@ import {FunctionTranslationsPackage} from './FunctionRegistry'
 
 export { 
   FunctionPluginDefinition,
-  FunctionArgumentDefinition,
+  FunctionArgument,
   FunctionPlugin,
   ImplementedFunctions,
   FunctionMetadata,
diff --git a/src/interpreter/plugin/AbsPlugin.ts b/src/interpreter/plugin/AbsPlugin.ts
index 34de534580..078353f23c 100644
--- a/src/interpreter/plugin/AbsPlugin.ts
+++ b/src/interpreter/plugin/AbsPlugin.ts
@@ -11,13 +11,13 @@ export class AbsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ABS': {
       method: 'abs',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]}
     },
   }
 
   public abs(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, AbsPlugin.implementedFunctions.ABS, Math.abs)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ABS'), Math.abs)
   }
 }
diff --git a/src/interpreter/plugin/BitShiftPlugin.ts b/src/interpreter/plugin/BitShiftPlugin.ts
index 445dd87e7e..135bd8d23f 100644
--- a/src/interpreter/plugin/BitShiftPlugin.ts
+++ b/src/interpreter/plugin/BitShiftPlugin.ts
@@ -15,26 +15,26 @@ export class BitShiftPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'BITLSHIFT': {
       method: 'bitlshift',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'integer', minValue: 0 },
         { argumentType: 'integer', minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
-      ]
+      ]}
     },
     'BITRSHIFT': {
       method: 'bitrshift',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'integer', minValue: 0 },
         { argumentType: 'integer', minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
-      ]
+      ]}
     },
   }
 
   public bitlshift(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BitShiftPlugin.implementedFunctions.BITLSHIFT, shiftLeft)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BITLSHIFT'), shiftLeft)
   }
 
   public bitrshift(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BitShiftPlugin.implementedFunctions.BITRSHIFT, shiftRight)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BITRSHIFT'), shiftRight)
   }
 }
 
diff --git a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
index 0be06e94c1..f3c04fbfe3 100644
--- a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
+++ b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
@@ -11,41 +11,41 @@ export class BitwiseLogicOperationsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'BITAND': {
       method: 'bitand',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'integer', minValue: 0 },
         { argumentType: 'integer', minValue: 0 },
-      ]
+      ]}
     },
     'BITOR': {
       method: 'bitor',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'integer', minValue: 0 },
         { argumentType: 'integer', minValue: 0 },
-      ]
+      ]}
     },
     'BITXOR': {
       method: 'bitxor',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'integer', minValue: 0 },
         { argumentType: 'integer', minValue: 0 },
-      ]
+      ]}
     },
   }
 
   public bitand(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITAND,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BITAND'),
       (left: number, right: number) => left & right
     )
   }
 
   public bitor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITOR,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BITOR'),
       (left: number, right: number) => left | right
     )
   }
 
   public bitxor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BitwiseLogicOperationsPlugin.implementedFunctions.BITXOR,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BITXOR'),
       (left: number, right: number) => left ^ right
     )
   }
diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index 4b545137e2..6ed398342c 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -15,80 +15,98 @@ export class BooleanPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'TRUE': {
       method: 'literalTrue',
-      parameters: [],
+      parameters: {list: []},
     },
     'FALSE': {
       method: 'literalFalse',
-      parameters: [],
+      parameters: {list: []},
     },
     'IF': {
       method: 'conditionalIf',
-      parameters: [
-        { argumentType: 'boolean' },
-        { argumentType: 'scalar' },
-        { argumentType: 'scalar', defaultValue: false },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'boolean'},
+          {argumentType: 'scalar'},
+          {argumentType: 'scalar', defaultValue: false},
+        ]
+      },
     },
     'AND': {
       method: 'and',
-      parameters: [
-        { argumentType: 'boolean' },
-      ],
-      repeatedArg: true,
-      expandRanges: true,
+      parameters: {
+        list: [
+          {argumentType: 'boolean'},
+        ],
+        repeatedArg: true,
+        expandRanges: true,
+      },
     },
     'OR': {
       method: 'or',
-      parameters: [
-        { argumentType: 'boolean' },
-      ],
-      repeatedArg: true,
-      expandRanges: true,
+      parameters: {
+        list: [
+          {argumentType: 'boolean'},
+        ],
+        repeatedArg: true,
+        expandRanges: true,
+      },
     },
     'XOR': {
       method: 'xor',
-      parameters: [
-        { argumentType: 'boolean' },
-      ],
-      repeatedArg: true,
-      expandRanges: true,
+      parameters: {
+        list: [
+          {argumentType: 'boolean'},
+        ],
+        repeatedArg: true,
+        expandRanges: true,
+      },
     },
     'NOT': {
       method: 'not',
-      parameters: [
-        { argumentType: 'boolean' },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'boolean'},
+        ]
+      },
     },
     'SWITCH': {
       method: 'switch',
-      parameters: [
-        { argumentType: 'noerror' },
-        { argumentType: 'scalar' },
-        { argumentType: 'scalar' },
-      ],
-      repeatedArg: true,
+      parameters: {
+        list: [
+          {argumentType: 'noerror'},
+          {argumentType: 'scalar'},
+          {argumentType: 'scalar'},
+        ],
+        repeatedArg: true,
+      },
     },
     'IFERROR': {
       method: 'iferror',
-      parameters: [
-        { argumentType: 'scalar' },
-        { argumentType: 'scalar' },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'scalar'},
+          {argumentType: 'scalar'},
+        ]
+      },
     },
     'IFNA': {
       method: 'ifna',
-      parameters: [
-        { argumentType: 'scalar' },
-        { argumentType: 'scalar' },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'scalar'},
+          {argumentType: 'scalar'},
+        ]
+      },
     },
     'CHOOSE': {
       method: 'choose',
-      parameters: [
-        { argumentType: 'number' },
-        { argumentType: 'scalar' },
-      ],
-      repeatedArg: true,
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'scalar'},
+        ],
+        repeatedArg: true,
+      },
     },
   }
 
@@ -101,7 +119,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public literalTrue(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.TRUE, () => true)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('TRUE'), () => true)
   }
 
   /**
@@ -113,7 +131,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public literalFalse(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.FALSE, () => false)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('FALSE'), () => false)
   }
 
   /**
@@ -125,8 +143,8 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public conditionalIf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InterpreterValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IF, (condition, arg2, arg3) => {
-        return condition ? arg2 : arg3
+    return this.runFunction(ast.args, formulaAddress, this.parameters('IF'), (condition, arg2, arg3) => {
+      return condition ? arg2 : arg3
     })
   }
 
@@ -139,8 +157,8 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public and(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.AND,
-      (...args) => !args.some( (arg: boolean) => !arg)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('AND'),
+      (...args) => !args.some((arg: boolean) => !arg)
     )
   }
 
@@ -153,37 +171,37 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public or(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.OR,
-      (...args) => args.some( (arg: boolean) => arg)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('OR'),
+      (...args) => args.some((arg: boolean) => arg)
     )
   }
 
   public not(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.NOT, (arg) => !arg)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('NOT'), (arg) => !arg)
   }
 
   public xor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.XOR, (...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('XOR'), (...args) => {
       let cnt = 0
       args.forEach((arg: boolean) => {
-        if( arg ) {
+        if (arg) {
           cnt++
         }
       })
-      return (cnt%2) === 1
+      return (cnt % 2) === 1
     })
   }
 
   public switch(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.SWITCH, (selector, ...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('SWITCH'), (selector, ...args) => {
       const n = args.length
-      let i  = 0
+      let i = 0
       for (; i + 1 < n; i += 2) {
         if (args[i] instanceof CellError) {
           continue
         }
         if (this.interpreter.arithmeticHelper.compare(selector, args[i] as InternalNoErrorCellValue) === 0) {
-          return args[i+1]
+          return args[i + 1]
         }
       }
       if (i < n) {
@@ -195,8 +213,8 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public iferror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IFERROR, (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
-      if(arg1 instanceof CellError) {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('IFERROR'), (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
+      if (arg1 instanceof CellError) {
         return arg2
       } else {
         return arg1
@@ -205,8 +223,8 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public ifna(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.IFNA, (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
-      if(arg1 instanceof CellError && arg1.type === ErrorType.NA) {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('IFNA'), (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
+      if (arg1 instanceof CellError && arg1.type === ErrorType.NA) {
         return arg2
       } else {
         return arg1
@@ -215,11 +233,11 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public choose(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, BooleanPlugin.implementedFunctions.CHOOSE, (selector, ...args) => {
-      if(selector !== Math.round(selector) || selector<1 || selector > args.length) {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('CHOOSE'), (selector, ...args) => {
+      if (selector !== Math.round(selector) || selector < 1 || selector > args.length) {
         return new CellError(ErrorType.NUM)
       }
-      return args[selector-1]
+      return args[selector - 1]
     })
   }
 }
diff --git a/src/interpreter/plugin/CharPlugin.ts b/src/interpreter/plugin/CharPlugin.ts
index 47b60222bf..3e4f318307 100644
--- a/src/interpreter/plugin/CharPlugin.ts
+++ b/src/interpreter/plugin/CharPlugin.ts
@@ -11,14 +11,16 @@ export class CharPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CHAR': {
       method: 'char',
-      parameters: [
-        { argumentType: 'number' }
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'}
+        ],
+      }
     },
   }
 
   public char(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, CharPlugin.implementedFunctions.CHAR, (value: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('CHAR'), (value: number) => {
       if (value < 1 || value > 255) {
         return new CellError(ErrorType.NUM)
       }
diff --git a/src/interpreter/plugin/CodePlugin.ts b/src/interpreter/plugin/CodePlugin.ts
index 27974d6797..62ecfa1023 100644
--- a/src/interpreter/plugin/CodePlugin.ts
+++ b/src/interpreter/plugin/CodePlugin.ts
@@ -11,14 +11,16 @@ export class CodePlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CODE': {
       method: 'code',
-      parameters: [
-        { argumentType: 'string' }
-        ],
+      parameters: {
+        list: [
+          {argumentType: 'string'}
+        ]
+      },
     },
   }
 
   public code(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, CodePlugin.implementedFunctions.CODE, (value: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('CODE'), (value: string) => {
       if (value.length === 0) {
         return new CellError(ErrorType.VALUE)
       }
diff --git a/src/interpreter/plugin/CountUniquePlugin.ts b/src/interpreter/plugin/CountUniquePlugin.ts
index 32569ad9bb..e20965f3eb 100644
--- a/src/interpreter/plugin/CountUniquePlugin.ts
+++ b/src/interpreter/plugin/CountUniquePlugin.ts
@@ -14,11 +14,13 @@ export class CountUniquePlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'COUNTUNIQUE': {
       method: 'countunique',
-      parameters: [
-        { argumentType: 'scalar' },
-      ],
-      repeatedArg: true,
-      expandRanges: true,
+      parameters: {
+        list: [
+          {argumentType: 'scalar'},
+        ],
+        repeatedArg: true,
+        expandRanges: true,
+      },
     },
   }
 
@@ -31,11 +33,11 @@ export class CountUniquePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public countunique(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, CountUniquePlugin.implementedFunctions.COUNTUNIQUE, (...args: InternalScalarValue[]) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('COUNTUNIQUE'), (...args: InternalScalarValue[]) => {
       const valuesSet = new Set<number | string | boolean | EmptyValueType>()
       const errorsSet = new Set<ErrorType>()
 
-      for (const scalarValue  of args) {
+      for (const scalarValue of args) {
         if (scalarValue instanceof CellError) {
           errorsSet.add(scalarValue.type)
         } else if (scalarValue !== '') {
diff --git a/src/interpreter/plugin/DegreesPlugin.ts b/src/interpreter/plugin/DegreesPlugin.ts
index 8a08df9d19..05c82c4de5 100644
--- a/src/interpreter/plugin/DegreesPlugin.ts
+++ b/src/interpreter/plugin/DegreesPlugin.ts
@@ -11,14 +11,16 @@ export class DegreesPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DEGREES': {
       method: 'degrees',
-      parameters: [
-        { argumentType: 'number' }
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'}
+        ]
+      },
     },
   }
 
   public degrees(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, DegreesPlugin.implementedFunctions.DEGREES,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DEGREES'),
       (arg) => arg * (180 / Math.PI)
     )
   }
diff --git a/src/interpreter/plugin/DeltaPlugin.ts b/src/interpreter/plugin/DeltaPlugin.ts
index 631f280c4f..5ecba964a5 100644
--- a/src/interpreter/plugin/DeltaPlugin.ts
+++ b/src/interpreter/plugin/DeltaPlugin.ts
@@ -11,15 +11,17 @@ export class DeltaPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DELTA': {
       method: 'delta',
-      parameters: [
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number', defaultValue: 0},
+        ]
+      },
     },
   }
 
   public delta(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, DeltaPlugin.implementedFunctions.DELTA,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DELTA'),
       (left: number, right: number) => (left === right ? 1 : 0)
     )
   }
diff --git a/src/interpreter/plugin/ErrorFunctionPlugin.ts b/src/interpreter/plugin/ErrorFunctionPlugin.ts
index 1afbdb682c..d5930243ad 100644
--- a/src/interpreter/plugin/ErrorFunctionPlugin.ts
+++ b/src/interpreter/plugin/ErrorFunctionPlugin.ts
@@ -11,22 +11,26 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ERF': {
       method: 'erf',
-      parameters: [
-        { argumentType: 'number' },
-        { argumentType: 'number', optionalArg: true},
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number', optionalArg: true},
+        ]
+      },
     },
     'ERFC': {
       method: 'erfc',
-      parameters: [
-        { argumentType: 'number' }
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'}
+        ]
+      },
     },
   }
 
   public erf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, ErrorFunctionPlugin.implementedFunctions.ERF, (lowerBound, upperBound) => {
-      if(upperBound===undefined) {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ERF'), (lowerBound, upperBound) => {
+      if (upperBound === undefined) {
         return erf(lowerBound)
       } else {
         return erf(upperBound) - erf(lowerBound)
@@ -35,7 +39,7 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
   }
 
   public erfc(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, ErrorFunctionPlugin.implementedFunctions.ERFC, erfc)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ERFC'), erfc)
   }
 }
 
diff --git a/src/interpreter/plugin/ExpPlugin.ts b/src/interpreter/plugin/ExpPlugin.ts
index af1286cedd..7350cbfbc5 100644
--- a/src/interpreter/plugin/ExpPlugin.ts
+++ b/src/interpreter/plugin/ExpPlugin.ts
@@ -11,9 +11,9 @@ export class ExpPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'EXP': {
       method: 'exp',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]},
     },
   }
 
@@ -26,6 +26,6 @@ export class ExpPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public exp(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, ExpPlugin.implementedFunctions.EXP, Math.exp)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('EXP'), Math.exp)
   }
 }
diff --git a/src/interpreter/plugin/FinancialPlugin.ts b/src/interpreter/plugin/FinancialPlugin.ts
index 1c904b3ef7..5f98e39f0f 100644
--- a/src/interpreter/plugin/FinancialPlugin.ts
+++ b/src/interpreter/plugin/FinancialPlugin.ts
@@ -11,71 +11,79 @@ export class FinancialPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'PMT': {
       method: 'pmt',
-      parameters: [
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0 },
-        { argumentType: 'number', defaultValue: 0 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number', defaultValue: 0},
+          {argumentType: 'number', defaultValue: 0},
+        ]
+      },
     },
     'IPMT': {
       method: 'ipmt',
-      parameters: [
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0 },
-        { argumentType: 'number', defaultValue: 0 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number', defaultValue: 0},
+          {argumentType: 'number', defaultValue: 0},
+        ]
+      },
     },
     'PPMT': {
       method: 'ppmt',
-      parameters: [
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0 },
-        { argumentType: 'number', defaultValue: 0 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number', defaultValue: 0},
+          {argumentType: 'number', defaultValue: 0},
+        ]
+      },
     },
     'FV': {
       method: 'fv',
-      parameters: [
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0 },
-        { argumentType: 'number', defaultValue: 0 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number', defaultValue: 0},
+          {argumentType: 'number', defaultValue: 0},
+        ]
+      },
     },
   }
 
   public pmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.PMT, pmtCore)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('PMT'), pmtCore)
   }
 
   public ipmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.IPMT, ipmtCore)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('IPMT'), ipmtCore)
   }
 
   public ppmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.PPMT, ppmtCore)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('PPMT'), ppmtCore)
   }
 
   public fv(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, FinancialPlugin.implementedFunctions.FV, fvCore)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('FV'), fvCore)
   }
 }
 
 function pmtCore(rate: number, periods: number, present: number, future: number, type: number): number {
   if (rate === 0) {
-    return (- present - future) / periods
+    return (-present - future) / periods
   } else {
     const term = Math.pow(1 + rate, periods)
-    return (future * rate + present * rate * term) * (type !== 0 ? 1 / (1 + rate) : 1) / (1-term)
+    return (future * rate + present * rate * term) * (type !== 0 ? 1 / (1 + rate) : 1) / (1 - term)
   }
 }
 
@@ -90,10 +98,10 @@ function ipmtCore(rate: number, period: number, periods: number, present: number
 
 function fvCore(rate: number, periods: number, payment: number, value: number, type: number): number {
   if (rate === 0) {
-    return - value - payment * periods
+    return -value - payment * periods
   } else {
     const term = Math.pow(1 + rate, periods)
-    return payment * (type !== 0 ? (1 + rate) : 1) * (1 - term) / rate  - value * term
+    return payment * (type !== 0 ? (1 + rate) : 1) * (1 - term) / rate - value * term
   }
 }
 
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index be5d68d692..d736288f59 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -3,7 +3,6 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import assert from 'assert'
 import {AbsoluteCellRange} from '../../AbsoluteCellRange'
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ColumnSearchStrategy} from '../../ColumnSearch/ColumnSearchStrategy'
@@ -21,9 +20,7 @@ export interface ImplementedFunctions {
 
 export interface FunctionMetadata {
   method: string,
-  parameters?: FunctionArgumentDefinition[],
-  repeatedArg?: boolean,
-  expandRanges?: boolean,
+  parameters?: FunctionArgumentsDefinition,
   isVolatile?: boolean,
   isDependentOnSheetStructureChange?: boolean,
   doesNotNeedArgumentsToBeComputed?: boolean,
@@ -37,11 +34,16 @@ export interface FunctionPluginDefinition {
 
 export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerror' | 'range' | 'integer'
 
-export interface FunctionArgumentDefinition {
+export interface FunctionArgumentsDefinition {
+  list: FunctionArgument[],
+  repeatedArg?: boolean,
+  expandRanges?: boolean,
+}
+
+export interface FunctionArgument {
   argumentType: string,
   defaultValue?: InternalScalarValue,
-  softCoerce?: boolean, //failed coerce makes function ignore the arg instead of producing error
-  optionalArg?: boolean, //
+  optionalArg?: boolean,
   minValue?: number,
   maxValue?: number,
   lessThan?: number,
@@ -101,7 +103,7 @@ export abstract class FunctionPlugin {
 
   public coerceScalarToNumberOrError = (arg: InternalScalarValue): number | CellError => this.interpreter.arithmeticHelper.coerceScalarToNumberOrError(arg)
 
-  public coerceToType(arg: InterpreterValue, coercedType: FunctionArgumentDefinition): Maybe<InterpreterValue> {
+  public coerceToType(arg: InterpreterValue, coercedType: FunctionArgument): Maybe<InterpreterValue> {
     if(arg instanceof SimpleRangeValue) {
       if(coercedType.argumentType === 'range') {
         return arg
@@ -150,17 +152,18 @@ export abstract class FunctionPlugin {
   protected runFunction = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
-    functionDefinition: FunctionMetadata,
+    functionDefinition: FunctionArgumentsDefinition,
     fn: (...arg: any) => InternalScalarValue
   ) => {
-    const argumentDefinitions: FunctionArgumentDefinition[] = functionDefinition.parameters!
-    assert(argumentDefinitions !== undefined)
+    const argumentDefinitions: FunctionArgument[] = functionDefinition.list
     let scalarValues: [InterpreterValue, boolean][]
+
     if(functionDefinition.expandRanges) {
       scalarValues = [...this.iterateOverScalarValues(args, formulaAddress)]
     } else {
       scalarValues = args.map((ast) => [this.evaluateAst(ast, formulaAddress), false])
     }
+
     const coercedArguments: Maybe<InterpreterValue>[] = []
 
     let argCoerceFailure: Maybe<CellError> = undefined
@@ -206,10 +209,11 @@ export abstract class FunctionPlugin {
     return argCoerceFailure ?? fn(...coercedArguments)
   }
 
-  protected evaluateArgOrDefault = (formulaAddress: SimpleCellAddress, argAst?: Ast, defaultValue?: InternalScalarValue): InterpreterValue => {
-    if (argAst !== undefined) {
-      return this.evaluateAst(argAst, formulaAddress)
+  protected parameters(name: string): FunctionArgumentsDefinition {
+    const params = (this.constructor as FunctionPluginDefinition).implementedFunctions[name]?.parameters
+    if (params !== undefined) {
+      return params
     }
-    return defaultValue ?? new CellError(ErrorType.NA)
+    throw new Error('FIXME Should not be undefined')
   }
-}
+}
\ No newline at end of file
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 99b9b2828a..390e0694fd 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -15,39 +15,39 @@ export class InformationPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISERROR': {
       method: 'iserror',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'scalar'}
-      ]
+      ]}
     },
     'ISBLANK': {
       method: 'isblank',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'scalar'}
-      ]
+      ]}
     },
     'ISNUMBER': {
       method: 'isnumber',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'scalar'}
-      ]
+      ]}
     },
     'ISLOGICAL': {
       method: 'islogical',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'scalar'}
-      ]
+      ]}
     },
     'ISTEXT': {
       method: 'istext',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'scalar'}
-      ]
+      ]}
     },
     'ISNONTEXT': {
       method: 'isnontext',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'scalar'}
-      ]
+      ]}
     },
     'COLUMNS': {
       method: 'columns',
@@ -73,7 +73,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public iserror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISERROR, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISERROR'), (arg: InternalScalarValue) =>
       (arg instanceof CellError)
     )
   }
@@ -87,7 +87,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isblank(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISBLANK, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISBLANK'), (arg: InternalScalarValue) =>
       (arg === EmptyValue)
     )
   }
@@ -101,7 +101,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isnumber(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNUMBER, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISNUMBER'), (arg: InternalScalarValue) =>
       (typeof arg === 'number')
     )
   }
@@ -115,7 +115,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public islogical(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISLOGICAL, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISLOGICAL'), (arg: InternalScalarValue) =>
       (typeof arg === 'boolean')
     )
   }
@@ -129,7 +129,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public istext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISTEXT, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISTEXT'), (arg: InternalScalarValue) =>
       (typeof arg === 'string')
     )
   }
@@ -143,7 +143,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isnontext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNONTEXT, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISNONTEXT'), (arg: InternalScalarValue) =>
       (typeof arg !== 'string')
     )
   }
diff --git a/src/interpreter/plugin/IsEvenPlugin.ts b/src/interpreter/plugin/IsEvenPlugin.ts
index 37bfd85cc5..f8154d7b4e 100644
--- a/src/interpreter/plugin/IsEvenPlugin.ts
+++ b/src/interpreter/plugin/IsEvenPlugin.ts
@@ -11,14 +11,14 @@ export class IsEvenPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISEVEN': {
       method: 'iseven',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number'}
-      ]
+      ]}
     },
   }
 
   public iseven(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, IsEvenPlugin.implementedFunctions.ISEVEN,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISEVEN'),
       (val) => (val % 2 === 0)
     )
   }
diff --git a/src/interpreter/plugin/IsOddPlugin.ts b/src/interpreter/plugin/IsOddPlugin.ts
index b83e621d02..9398305409 100644
--- a/src/interpreter/plugin/IsOddPlugin.ts
+++ b/src/interpreter/plugin/IsOddPlugin.ts
@@ -11,14 +11,16 @@ export class IsOddPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISODD': {
       method: 'isodd',
-      parameters: [
-        { argumentType: 'number'}
-      ]
+      parameters: {
+        list: [
+          {argumentType: 'number'}
+        ]
+      }
     },
   }
 
   public isodd(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, IsOddPlugin.implementedFunctions.ISODD,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISODD'),
       (val) => (val % 2 === 1)
     )
   }
diff --git a/src/interpreter/plugin/LogarithmPlugin.ts b/src/interpreter/plugin/LogarithmPlugin.ts
index 0884a1128c..dafbbacd87 100644
--- a/src/interpreter/plugin/LogarithmPlugin.ts
+++ b/src/interpreter/plugin/LogarithmPlugin.ts
@@ -12,36 +12,42 @@ export class LogarithmPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'LOG10': {
       method: 'log10',
-      parameters: [
-        { argumentType: 'number' }
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'}
+        ]
+      },
     },
     'LOG': {
       method: 'log',
-      parameters: [
-        { argumentType: 'number', greaterThan: 0 },
-        { argumentType: 'number', defaultValue: 10, greaterThan: 0 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number', greaterThan: 0},
+          {argumentType: 'number', defaultValue: 10, greaterThan: 0},
+        ]
+      },
     },
     'LN': {
       method: 'ln',
-      parameters: [
-        { argumentType: 'number' }
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'number'}
+        ]
+      },
     },
   }
 
   public log10(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LOG10, Math.log10)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('LOG10'), Math.log10)
   }
 
   public log(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LOG,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('LOG'),
       (arg: number, base: number) => Math.log(arg) / Math.log(base)
     )
   }
 
   public ln(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, LogarithmPlugin.implementedFunctions.LN, Math.log)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('LN'), Math.log)
   }
 }
diff --git a/src/interpreter/plugin/MathConstantsPlugin.ts b/src/interpreter/plugin/MathConstantsPlugin.ts
index bafc1a460b..174e2f8571 100644
--- a/src/interpreter/plugin/MathConstantsPlugin.ts
+++ b/src/interpreter/plugin/MathConstantsPlugin.ts
@@ -14,22 +14,22 @@ export class MathConstantsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'PI': {
       method: 'pi',
-      parameters: [],
+      parameters: {list: []},
     },
     'E': {
       method: 'e',
-      parameters: [],
+      parameters: {list: []},
     },
   }
 
   public pi(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, MathConstantsPlugin.implementedFunctions.PI,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('PI'),
       () => PI
     )
   }
 
   public e(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, MathConstantsPlugin.implementedFunctions.E,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('E'),
       () => E
     )
   }
diff --git a/src/interpreter/plugin/MedianPlugin.ts b/src/interpreter/plugin/MedianPlugin.ts
index 11f7cba99d..4163ba09aa 100644
--- a/src/interpreter/plugin/MedianPlugin.ts
+++ b/src/interpreter/plugin/MedianPlugin.ts
@@ -15,11 +15,13 @@ export class MedianPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'MEDIAN': {
       method: 'median',
-      parameters: [
-        { argumentType: 'noerror' },
-      ],
-      repeatedArg: true,
-      expandRanges: true,
+      parameters: {
+        list: [
+          {argumentType: 'noerror'},
+        ],
+        repeatedArg: true,
+        expandRanges: true,
+      },
     },
   }
 
@@ -32,7 +34,7 @@ export class MedianPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public median(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, MedianPlugin.implementedFunctions.MEDIAN, (...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('MEDIAN'), (...args) => {
       const values: number[] = args.filter((val: InternalScalarValue) => (typeof val === 'number'))
       if (values.length === 0) {
         return new CellError(ErrorType.NUM)
diff --git a/src/interpreter/plugin/ModuloPlugin.ts b/src/interpreter/plugin/ModuloPlugin.ts
index e5f5ea3e35..cae4bcdbcd 100644
--- a/src/interpreter/plugin/ModuloPlugin.ts
+++ b/src/interpreter/plugin/ModuloPlugin.ts
@@ -11,15 +11,15 @@ export class ModuloPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'MOD': {
       method: 'mod',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' },
         { argumentType: 'number' },
-      ],
+      ]},
     },
   }
 
   public mod(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, ModuloPlugin.implementedFunctions.MOD, (dividend: number, divisor: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('MOD'), (dividend: number, divisor: number) => {
       if (divisor === 0) {
         return new CellError(ErrorType.DIV_BY_ZERO)
       } else {
diff --git a/src/interpreter/plugin/PowerPlugin.ts b/src/interpreter/plugin/PowerPlugin.ts
index 53150065b3..59ed57f72e 100644
--- a/src/interpreter/plugin/PowerPlugin.ts
+++ b/src/interpreter/plugin/PowerPlugin.ts
@@ -11,14 +11,14 @@ export class PowerPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'POWER': {
       method: 'power',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' },
         { argumentType: 'number' },
-      ],
+      ]},
     },
   }
 
   public power(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, PowerPlugin.implementedFunctions.POWER, Math.pow)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('POWER'), Math.pow)
   }
 }
diff --git a/src/interpreter/plugin/RadiansPlugin.ts b/src/interpreter/plugin/RadiansPlugin.ts
index e673b84b4b..ac0af90e0d 100644
--- a/src/interpreter/plugin/RadiansPlugin.ts
+++ b/src/interpreter/plugin/RadiansPlugin.ts
@@ -11,14 +11,14 @@ export class RadiansPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'RADIANS': {
       method: 'radians',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]},
     },
   }
 
   public radians(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadiansPlugin.implementedFunctions.RADIANS,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('RADIANS'),
       (arg) => arg * (Math.PI / 180)
     )
   }
diff --git a/src/interpreter/plugin/RadixConversionPlugin.ts b/src/interpreter/plugin/RadixConversionPlugin.ts
index 7ddb7075ff..2bb0235298 100644
--- a/src/interpreter/plugin/RadixConversionPlugin.ts
+++ b/src/interpreter/plugin/RadixConversionPlugin.ts
@@ -19,82 +19,82 @@ export class RadixConversionPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DEC2BIN': {
       method: 'dec2bin',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number', minValue: minValFromBase(2), maxValue: maxValFromBase(2) },
         { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
-      ],
+      ]},
     },
     'DEC2OCT': {
       method: 'dec2oct',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number', minValue: minValFromBase(8), maxValue: maxValFromBase(8) },
         { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
-      ],
+      ]},
     },
     'DEC2HEX': {
       method: 'dec2hex',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number', minValue: minValFromBase(16), maxValue: maxValFromBase(16) },
         { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
-      ],
+      ]},
     },
     'BIN2DEC': {
       method: 'bin2dec',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'string' }
-      ],
+      ]},
     },
     'BIN2OCT': {
       method: 'bin2oct',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'string' },
         { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
-      ],
+      ]},
     },
     'BIN2HEX': {
       method: 'bin2hex',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'string' },
         { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
-      ],
+      ]},
     },
     'DECIMAL': {
       method: 'decimal',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'string' },
         { argumentType: 'number', minValue: MIN_BASE, maxValue: MAX_BASE },
-      ],
+      ]},
     },
     'BASE': {
       method: 'base',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number', minValue: 0 },
         { argumentType: 'number', minValue: MIN_BASE, maxValue: MAX_BASE },
         { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
-      ],
+      ]},
     },
   }
 
   public dec2bin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.DEC2BIN,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DEC2BIN'),
       (value, places) => decimalToBaseWithExactPadding(value, 2, places)
     )
   }
 
   public dec2oct(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.DEC2OCT,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DEC2OCT'),
       (value, places) => decimalToBaseWithExactPadding(value, 8, places)
     )
   }
 
   public dec2hex(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.DEC2HEX,
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DEC2HEX'),
       (value, places) => decimalToBaseWithExactPadding(value, 16, places)
     )
   }
 
   public bin2dec(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.BIN2DEC, (binary) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BIN2DEC'), (binary) => {
         const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
         if(binaryWithSign === undefined) {
           return new CellError(ErrorType.NUM)
@@ -104,7 +104,7 @@ export class RadixConversionPlugin extends FunctionPlugin {
   }
 
   public bin2oct(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.BIN2OCT, (binary, places) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BIN2OCT'), (binary, places) => {
       const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
       if(binaryWithSign === undefined) {
         return new CellError(ErrorType.NUM)
@@ -114,7 +114,7 @@ export class RadixConversionPlugin extends FunctionPlugin {
   }
 
   public bin2hex(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.BIN2HEX, (binary, places) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BIN2HEX'), (binary, places) => {
       const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
       if(binaryWithSign === undefined) {
         return new CellError(ErrorType.NUM)
@@ -124,11 +124,11 @@ export class RadixConversionPlugin extends FunctionPlugin {
   }
 
   public base(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.BASE, decimalToBaseWithMinimumPadding)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('BASE'), decimalToBaseWithMinimumPadding)
   }
 
   public decimal(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RadixConversionPlugin.implementedFunctions.DECIMAL, (arg, base) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DECIMAL'), (arg, base) => {
       const input = coerceStringToBase(arg, base, DECIMAL_NUMBER_OF_BITS)
       if(input === undefined) {
         return new CellError(ErrorType.NUM)
diff --git a/src/interpreter/plugin/RandomPlugin.ts b/src/interpreter/plugin/RandomPlugin.ts
index f85a65c562..8fa32c1333 100644
--- a/src/interpreter/plugin/RandomPlugin.ts
+++ b/src/interpreter/plugin/RandomPlugin.ts
@@ -3,15 +3,15 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {ProcedureAst} from '../../parser'
 import {FunctionPlugin} from './FunctionPlugin'
 
 export class RandomPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'RAND': {
       method: 'rand',
-      parameters: [],
+      parameters: { list: [] },
       isVolatile: true,
     },
   }
@@ -26,6 +26,6 @@ export class RandomPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public rand(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RandomPlugin.implementedFunctions.RAND, Math.random)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('RAND'), Math.random)
   }
 }
diff --git a/src/interpreter/plugin/RoundingPlugin.ts b/src/interpreter/plugin/RoundingPlugin.ts
index b714c2c6f0..6ffa0c2444 100644
--- a/src/interpreter/plugin/RoundingPlugin.ts
+++ b/src/interpreter/plugin/RoundingPlugin.ts
@@ -21,62 +21,62 @@ export class RoundingPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ROUNDUP': {
       method: 'roundup',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' },
         { argumentType: 'number', defaultValue: 0},
-      ],
+      ]},
     },
     'ROUNDDOWN': {
       method: 'rounddown',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' },
         { argumentType: 'number', defaultValue: 0},
-      ],
+      ]},
     },
     'ROUND': {
       method: 'round',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' },
         { argumentType: 'number', defaultValue: 0},
-      ],
+      ]},
     },
     'TRUNC': {
       method: 'trunc',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' },
         { argumentType: 'number', defaultValue: 0},
-      ],
+      ]},
     },
     'INT': {
       method: 'intFunc',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]},
     },
     'EVEN': {
       method: 'even',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]},
     },
     'ODD': {
       method: 'odd',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]},
     },
     'CEILING': {
       method: 'ceiling',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' },
         { argumentType: 'number', defaultValue: 1 },
         { argumentType: 'number', defaultValue: 0 },
-      ],
+      ]},
     },
   }
 
   public roundup(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ROUNDDOWN, (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ROUNDDOWN'), (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.ceil(-numberToRound * placesMultiplier) / placesMultiplier
@@ -87,7 +87,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public rounddown(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ROUNDDOWN, (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ROUNDDOWN'), (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.floor(-numberToRound * placesMultiplier) / placesMultiplier
@@ -98,7 +98,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public round(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ROUND, (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ROUND'), (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.round(-numberToRound * placesMultiplier) / placesMultiplier
@@ -113,7 +113,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public intFunc(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.INT, (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('INT'), (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -Math.floor(-coercedNumberToRound)
       } else {
@@ -123,7 +123,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public even(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.EVEN, (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('EVEN'), (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -findNextEvenNumber(-coercedNumberToRound)
       } else {
@@ -133,7 +133,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public odd(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.ODD, (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ODD'), (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -findNextOddNumber(-coercedNumberToRound)
       } else {
@@ -143,7 +143,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public ceiling(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, RoundingPlugin.implementedFunctions.CEILING, (value: number, significance: number, mode: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('CEILING'), (value: number, significance: number, mode: number) => {
       if (significance === 0 || value === 0) {
         return 0
       }
diff --git a/src/interpreter/plugin/SqrtPlugin.ts b/src/interpreter/plugin/SqrtPlugin.ts
index 7ca2c1ab4b..f1b0174de2 100644
--- a/src/interpreter/plugin/SqrtPlugin.ts
+++ b/src/interpreter/plugin/SqrtPlugin.ts
@@ -11,13 +11,13 @@ export class SqrtPlugin extends  FunctionPlugin {
   public static implementedFunctions = {
     'SQRT': {
       method: 'sqrt',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]},
     },
   }
 
   public sqrt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, SqrtPlugin.implementedFunctions.SQRT, Math.sqrt)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('SQRT'), Math.sqrt)
   }
 }
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index fb6588beaf..4e758b5ba6 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -14,79 +14,101 @@ export class TextPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CONCATENATE': {
       method: 'concatenate',
-      parameters: [
-        { argumentType: 'string'}
-      ],
-      repeatedArg: true,
-      expandRanges: true,
+      parameters: {
+        list: [
+          {argumentType: 'string'}
+        ],
+        repeatedArg: true,
+        expandRanges: true,
+      },
     },
     'SPLIT': {
       method: 'split',
-      parameters: [
-        { argumentType: 'string' },
-        { argumentType: 'number' },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'},
+          {argumentType: 'number'},
+        ]
+      },
     },
     'LEN': {
       method: 'len',
-      parameters: [
-        { argumentType: 'string'}
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'}
+        ]
+      },
     },
     'TRIM': {
       method: 'trim',
-      parameters: [
-        { argumentType: 'string'}
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'}
+        ]
+      },
     },
     'PROPER': {
       method: 'proper',
-      parameters: [
-        { argumentType: 'string'}
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'}
+        ]
+      },
     },
     'CLEAN': {
       method: 'clean',
-      parameters: [
-        { argumentType: 'string'}
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'}
+        ]
+      },
     },
     'REPT': {
       method: 'rept',
-      parameters: [
-        { argumentType: 'string' },
-        { argumentType: 'number' },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'},
+          {argumentType: 'number'},
+        ]
+      },
     },
     'RIGHT': {
       method: 'right',
-      parameters: [
-        { argumentType: 'string' },
-        { argumentType: 'number', defaultValue: 1 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'},
+          {argumentType: 'number', defaultValue: 1},
+        ]
+      },
     },
     'LEFT': {
       method: 'left',
-      parameters: [
-        { argumentType: 'string' },
-        { argumentType: 'number', defaultValue: 1 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'},
+          {argumentType: 'number', defaultValue: 1},
+        ]
+      },
     },
     'SEARCH': {
       method: 'search',
-      parameters: [
-        { argumentType: 'string' },
-        { argumentType: 'string' },
-        { argumentType: 'number', defaultValue: 1 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'},
+          {argumentType: 'string'},
+          {argumentType: 'number', defaultValue: 1},
+        ]
+      },
     },
     'FIND': {
       method: 'find',
-      parameters: [
-        { argumentType: 'string' },
-        { argumentType: 'string' },
-        { argumentType: 'number', defaultValue: 1 },
-      ],
+      parameters: {
+        list: [
+          {argumentType: 'string'},
+          {argumentType: 'string'},
+          {argumentType: 'number', defaultValue: 1},
+        ]
+      },
     }
   }
 
@@ -99,7 +121,7 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public concatenate(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.CONCATENATE, (...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('CONCATENATE'), (...args) => {
       return ''.concat(...args)
     })
   }
@@ -113,7 +135,7 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public split(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.SPLIT, (stringToSplit: string, indexToUse: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('SPLIT'), (stringToSplit: string, indexToUse: number) => {
       const splittedString = stringToSplit.split(' ')
 
       if (indexToUse >= splittedString.length || indexToUse < 0) {
@@ -125,32 +147,32 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public len(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.LEN, (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('LEN'), (arg: string) => {
       return arg.length
     })
   }
 
   public trim(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.TRIM, (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('TRIM'), (arg: string) => {
       return arg.replace(/^ +| +$/g, '').replace(/ +/g, ' ')
     })
   }
 
   public proper(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.PROPER, (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('PROPER'), (arg: string) => {
       return arg.replace(/\w\S*/g, word => word.charAt(0).toUpperCase() + word.substr(1).toLowerCase())
     })
   }
 
   public clean(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.CLEAN, (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('CLEAN'), (arg: string) => {
       // eslint-disable-next-line no-control-regex
       return arg.replace(/[\u0000-\u001F]/g, '')
     })
   }
 
   public rept(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.REPT, (text: string, count: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('REPT'), (text: string, count: number) => {
       if (count < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -159,7 +181,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public right(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.RIGHT, (text: string, length: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('RIGHT'), (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       } else if (length === 0) {
@@ -170,7 +192,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public left(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.LEFT, (text: string, length: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('LEFT'), (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -179,7 +201,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public search(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.SEARCH, (pattern, text: string, startIndex: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('SEARCH'), (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }
@@ -199,7 +221,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public find(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TextPlugin.implementedFunctions.FIND, (pattern, text: string, startIndex: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('FIND'), (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }
diff --git a/src/interpreter/plugin/TrigonometryPlugin.ts b/src/interpreter/plugin/TrigonometryPlugin.ts
index 4b6365f125..e3615c4db7 100644
--- a/src/interpreter/plugin/TrigonometryPlugin.ts
+++ b/src/interpreter/plugin/TrigonometryPlugin.ts
@@ -15,52 +15,52 @@ export class TrigonometryPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ACOS': {
       method: 'acos',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]}
     },
     'ASIN': {
       method: 'asin',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]}
     },
     'COS': {
       method: 'cos',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]}
     },
     'SIN': {
       method: 'sin',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]}
     },
     'TAN': {
       method: 'tan',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]}
     },
     'ATAN': {
       method: 'atan',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]}
     },
     'ATAN2': {
       method: 'atan2',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' },
         { argumentType: 'number' },
-      ],
+      ]}
     },
     'COT': {
       method: 'ctg',
-      parameters: [
+      parameters: { list: [
         { argumentType: 'number' }
-      ],
+      ]}
     },
   }
 
@@ -73,35 +73,35 @@ export class TrigonometryPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public acos(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ACOS, Math.acos)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ACOS'), Math.acos)
   }
 
   public asin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ASIN, Math.asin)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ASIN'), Math.asin)
   }
 
   public cos(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.COS, Math.cos)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('COS'), Math.cos)
   }
 
   public sin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.SIN, Math.sin)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('SIN'), Math.sin)
   }
 
   public tan(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.TAN, Math.tan)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('TAN'), Math.tan)
   }
 
   public atan(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ATAN, Math.atan)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ATAN'), Math.atan)
   }
 
   public atan2(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.ATAN2, Math.atan2)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ATAN2'), Math.atan2)
   }
 
   public ctg(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, TrigonometryPlugin.implementedFunctions.COT, (coercedArg) => {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('COT'), (coercedArg) => {
       if (coercedArg === 0) {
         return new CellError(ErrorType.DIV_BY_ZERO)
       } else {

From 86a203cd0715c5bd3d6192c98c489216064ea15c Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Mon, 27 Jul 2020 16:36:56 +0200
Subject: [PATCH 59/97] .

---
 src/interpreter/plugin/FunctionPlugin.ts | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index d74ec3b99b..d0781dd567 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -13,10 +13,7 @@ import {Ast, ProcedureAst} from '../../parser'
 import {coerceScalarToBoolean, coerceScalarToString} from '../ArithmeticHelper'
 import {Interpreter} from '../Interpreter'
 import {InterpreterValue, SimpleRangeValue} from '../InterpreterValue'
-<<<<<<< HEAD
-=======
 import {Serialization} from '../../Serialization'
->>>>>>> develop
 
 export interface ImplementedFunctions {
   [formulaId: string]: FunctionMetadata,
@@ -222,4 +219,4 @@ export abstract class FunctionPlugin {
     }
     throw new Error('FIXME Should not be undefined')
   }
-}
\ No newline at end of file
+}

From 25ec51e7ef39926ac4c1e84cc041aa3f088b3357 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Tue, 28 Jul 2020 17:53:47 +0200
Subject: [PATCH 60/97] Median benchmark

---
 test/performance/1-basic.ts                  | 23 ++++++++++----------
 test/performance/sheets/median-evaluation.ts | 20 +++++++++++++++++
 2 files changed, 32 insertions(+), 11 deletions(-)
 create mode 100644 test/performance/sheets/median-evaluation.ts

diff --git a/test/performance/1-basic.ts b/test/performance/1-basic.ts
index e494e7db4a..ec72d88dfc 100644
--- a/test/performance/1-basic.ts
+++ b/test/performance/1-basic.ts
@@ -2,23 +2,24 @@ import {batch, benchmark, BenchmarkResult} from './benchmark'
 import {expectedValues as expectedValuesT, sheet as sheetTGenerator} from './sheets/05-sheet-t'
 import {expectedValues as expectedValuesA, sheet as sheetAGenerator} from './sheets/09-sheet-a'
 import {expectedValues as expectedValuesB, sheet as sheetBGenerator} from './sheets/10-sheet-b'
+import {sheet as median} from './sheets/median-evaluation'
 import {sheet as columnRangesGenerator} from './sheets/column-ranges'
 
 (() => {
-  const sheetA = sheetAGenerator()
-  const sheetB = sheetBGenerator()
-  const sheetT = sheetTGenerator()
-  const infiniteRanges = columnRangesGenerator()
+  // const sheetA = sheetAGenerator()
+  // const sheetB = sheetBGenerator()
+  // const sheetT = sheetTGenerator()
+  // const infiniteRanges = columnRangesGenerator()
 
   const result: BenchmarkResult[] = []
   batch(result,
-    () => benchmark('Sheet A', sheetA, expectedValuesA(sheetA), {numberOfRuns: 10}),
-    () => benchmark('Sheet B', sheetB, expectedValuesB(sheetB), {numberOfRuns: 10}),
-    () => benchmark('Sheet T', sheetT, expectedValuesT(sheetT), {numberOfRuns: 10}),
-    () => benchmark('Column ranges', infiniteRanges, [{
-      address: 'AX50',
-      value: 1.04519967355127e+63
-    }], {expectedTime: 1000, numberOfRuns: 10})
+    () => benchmark('Sheet A', median(), [], {numberOfRuns: 10}),
+    // () => benchmark('Sheet B', sheetB, expectedValuesB(sheetB), {numberOfRuns: 10}),
+    // () => benchmark('Sheet T', sheetT, expectedValuesT(sheetT), {numberOfRuns: 10}),
+    // () => benchmark('Column ranges', infiniteRanges, [{
+    //   address: 'AX50',
+    //   value: 1.04519967355127e+63
+    // }], {expectedTime: 1000, numberOfRuns: 10})
   )
 
   console.table(result.map(e => ({
diff --git a/test/performance/sheets/median-evaluation.ts b/test/performance/sheets/median-evaluation.ts
new file mode 100644
index 0000000000..a9f890d65d
--- /dev/null
+++ b/test/performance/sheets/median-evaluation.ts
@@ -0,0 +1,20 @@
+export function sheet(rows: number = 20000) {
+  const sheet = []
+  sheet.push(['1', '2', '3', '0', '0'])
+
+  let prev = 1
+
+  while (prev < rows) {
+    const rowToPush = [
+      `${prev + 1}`,
+      '2',
+      '=3*5',
+      `=A${prev}+D${prev}`,
+      `=OR(FALSE(), ISEVEN(MEDIAN(A${prev},B${prev},C${prev},D${prev})))`,
+    ]
+
+    sheet.push(rowToPush)
+    ++prev
+  }
+  return sheet
+}
\ No newline at end of file

From 5644dd5168150f6832fd89a25549a69c64ebb23e Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Tue, 28 Jul 2020 18:50:41 +0200
Subject: [PATCH 61/97] faster benchmark

---
 src/interpreter/CriterionFunctionCompute.ts |  2 +-
 src/interpreter/InterpreterValue.ts         | 37 ++++++++++++++++++---
 src/interpreter/plugin/CorrelPlugin.ts      |  4 +--
 src/interpreter/plugin/FunctionPlugin.ts    | 19 +++++++++--
 src/interpreter/plugin/SumprodPlugin.ts     |  4 +--
 5 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/src/interpreter/CriterionFunctionCompute.ts b/src/interpreter/CriterionFunctionCompute.ts
index 1a58fec692..89d61c9841 100644
--- a/src/interpreter/CriterionFunctionCompute.ts
+++ b/src/interpreter/CriterionFunctionCompute.ts
@@ -108,7 +108,7 @@ export class CriterionFunctionCompute<T> {
   private evaluateRangeValue(simpleValuesRange: SimpleRangeValue, conditions: Condition[]) {
     const criterionLambdas = conditions.map((condition) => condition.criterionPackage.lambda)
     const values = Array.from(simpleValuesRange.valuesFromTopLeftCorner()).map(this.mapFunction)[Symbol.iterator]()
-    const conditionsIterators = conditions.map((condition) => condition.conditionRange.valuesFromTopLeftCorner())
+    const conditionsIterators = conditions.map((condition) => condition.conditionRange.iterateValuesFromTopLeftCorner())
     const filteredValues = ifFilter(criterionLambdas, conditionsIterators, values)
     return this.reduceFunction(filteredValues)
   }
diff --git a/src/interpreter/InterpreterValue.ts b/src/interpreter/InterpreterValue.ts
index 614da03551..fbcf42811f 100644
--- a/src/interpreter/InterpreterValue.ts
+++ b/src/interpreter/InterpreterValue.ts
@@ -25,7 +25,17 @@ export class ArrayData {
     return this._hasOnlyNumbers
   }
 
-  public* valuesFromTopLeftCorner(): IterableIterator<InternalScalarValue> {
+  public valuesFromTopLeftCorner(): InternalScalarValue[] {
+    const ret = []
+    for (let i = 0; i < this.size.height; i++) {
+      for (let j = 0; j < this.size.width; j++) {
+        ret.push(this.data[i][j])
+      }
+    }
+    return ret
+  }
+
+  public* iterateValuesFromTopLeftCorner(): IterableIterator<InternalScalarValue> {
     for (let i = 0; i < this.size.height; i++) {
       for (let j = 0; j < this.size.width; j++) {
         yield this.data[i][j]
@@ -76,7 +86,7 @@ export class OnlyRangeData {
     this.ensureThatComputed()
 
     if (this._hasOnlyNumbers === undefined) {
-      for (const v of this.valuesFromTopLeftCorner()) {
+      for (const v of this.iterateValuesFromTopLeftCorner()) {
         if (typeof v !== 'number') {
           this._hasOnlyNumbers = false
           break
@@ -92,7 +102,20 @@ export class OnlyRangeData {
     return this._range
   }
 
-  public* valuesFromTopLeftCorner(): IterableIterator<InternalScalarValue> {
+  public valuesFromTopLeftCorner(): InternalScalarValue[] {
+    this.ensureThatComputed()
+
+    const ret = []
+    for (let i = 0; i < this.data!.length; i++) {
+      for (let j = 0; j < this.data![0].length; j++) {
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+        ret.push(this.data![i][j])
+      }
+    }
+    return ret
+  }
+
+  public* iterateValuesFromTopLeftCorner(): IterableIterator<InternalScalarValue> {
     this.ensureThatComputed()
 
     for (let i = 0; i < this.data!.length; i++) {
@@ -178,8 +201,12 @@ export class SimpleRangeValue {
     return this.data.raw()
   }
 
-  public* valuesFromTopLeftCorner(): IterableIterator<InternalScalarValue> {
-    yield *this.data.valuesFromTopLeftCorner()
+  public valuesFromTopLeftCorner(): InternalScalarValue[] {
+    return this.data.valuesFromTopLeftCorner()
+  }
+
+  public* iterateValuesFromTopLeftCorner(): IterableIterator<InternalScalarValue> {
+    yield *this.data.iterateValuesFromTopLeftCorner()
   }
 
   public numberOfElements(): number {
diff --git a/src/interpreter/plugin/CorrelPlugin.ts b/src/interpreter/plugin/CorrelPlugin.ts
index 6992c923b8..4020724bcc 100644
--- a/src/interpreter/plugin/CorrelPlugin.ts
+++ b/src/interpreter/plugin/CorrelPlugin.ts
@@ -39,8 +39,8 @@ export class CorrelPlugin extends FunctionPlugin {
   }
 
   private computePearson(dataX: SimpleRangeValue, dataY: SimpleRangeValue): number | CellError {
-    const xit = dataX.valuesFromTopLeftCorner()
-    const yit = dataY.valuesFromTopLeftCorner()
+    const xit = dataX.iterateValuesFromTopLeftCorner()
+    const yit = dataY.iterateValuesFromTopLeftCorner()
     let x, y
 
     let count = 0
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index d0781dd567..b41a3ae8c3 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -85,7 +85,7 @@ export abstract class FunctionPlugin {
     for (const argAst of asts) {
       const value = this.evaluateAst(argAst, formulaAddress)
       if (value instanceof SimpleRangeValue) {
-        for (const scalarValue of value.valuesFromTopLeftCorner()) {
+        for (const scalarValue of value.iterateValuesFromTopLeftCorner()) {
           yield [scalarValue, true]
         }
       } else {
@@ -94,6 +94,21 @@ export abstract class FunctionPlugin {
     }
   }
 
+  protected listOfScalarValues(asts: Ast[], formulaAddress: SimpleCellAddress): [InternalScalarValue, boolean][] {
+    const ret: [InternalScalarValue, boolean][] = []
+    for (const argAst of asts) {
+      const value = this.evaluateAst(argAst, formulaAddress)
+      if (value instanceof SimpleRangeValue) {
+        for (const scalarValue of value.valuesFromTopLeftCorner()) {
+          ret.push([scalarValue, true])
+        }
+      } else {
+        ret.push([value,false])
+      }
+    }
+    return ret
+  }
+
   protected computeListOfValuesInRange(range: AbsoluteCellRange): InternalScalarValue[] {
     const values: InternalScalarValue[] = []
     for (const cellFromRange of range.addresses(this.dependencyGraph)) {
@@ -162,7 +177,7 @@ export abstract class FunctionPlugin {
     let scalarValues: [InterpreterValue, boolean][]
 
     if(functionDefinition.expandRanges) {
-      scalarValues = [...this.iterateOverScalarValues(args, formulaAddress)]
+      scalarValues = this.listOfScalarValues(args, formulaAddress)
     } else {
       scalarValues = args.map((ast) => [this.evaluateAst(ast, formulaAddress), false])
     }
diff --git a/src/interpreter/plugin/SumprodPlugin.ts b/src/interpreter/plugin/SumprodPlugin.ts
index 76ab5e861b..f5ed723e28 100644
--- a/src/interpreter/plugin/SumprodPlugin.ts
+++ b/src/interpreter/plugin/SumprodPlugin.ts
@@ -38,8 +38,8 @@ export class SumprodPlugin extends FunctionPlugin {
   private reduceSumprod(left: SimpleRangeValue, right: SimpleRangeValue): number | CellError {
     let result = 0
 
-    const lit = left.valuesFromTopLeftCorner()
-    const rit = right.valuesFromTopLeftCorner()
+    const lit = left.iterateValuesFromTopLeftCorner()
+    const rit = right.iterateValuesFromTopLeftCorner()
     let l, r
 
     while (l = lit.next(), r = rit.next(), !l.done && !r.done) {

From 6d050358150ae5deee4da37e861513fcd2fe67c3 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Tue, 28 Jul 2020 19:39:49 +0200
Subject: [PATCH 62/97] fix

---
 src/interpreter/plugin/FunctionPlugin.ts | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index b41a3ae8c3..76d4a436a2 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -81,19 +81,6 @@ export abstract class FunctionPlugin {
     return this.interpreter.evaluateAst(ast, formulaAddress)
   }
 
-  protected* iterateOverScalarValues(asts: Ast[], formulaAddress: SimpleCellAddress): IterableIterator<[InternalScalarValue, boolean]> {
-    for (const argAst of asts) {
-      const value = this.evaluateAst(argAst, formulaAddress)
-      if (value instanceof SimpleRangeValue) {
-        for (const scalarValue of value.iterateValuesFromTopLeftCorner()) {
-          yield [scalarValue, true]
-        }
-      } else {
-        yield [value, false]
-      }
-    }
-  }
-
   protected listOfScalarValues(asts: Ast[], formulaAddress: SimpleCellAddress): [InternalScalarValue, boolean][] {
     const ret: [InternalScalarValue, boolean][] = []
     for (const argAst of asts) {
@@ -103,7 +90,7 @@ export abstract class FunctionPlugin {
           ret.push([scalarValue, true])
         }
       } else {
-        ret.push([value,false])
+        ret.push([value, false])
       }
     }
     return ret

From 53c955d31db9d3aa955fc359a43feb5d1e59c90c Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 29 Jul 2020 12:14:31 +0200
Subject: [PATCH 63/97] changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90815da2f3..8a8a2879d1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 - Operation `moveCells` creating cyclic dependencies does not cause losing original formula. (#479)
+- Simplified adding new function modules, reworked (simplified) implementations of existing modules.
 
 ### Fixed
 - Fixed hardcoding of languages in i18n tests. (#471)

From 473fe33808f853a4b800855f7c11a093af8709e2 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 29 Jul 2020 14:48:51 +0200
Subject: [PATCH 64/97] refactor

---
 src/interpreter/plugin/DatePlugin.ts     | 236 ++++++++---------------
 src/interpreter/plugin/FunctionPlugin.ts |  38 ++--
 2 files changed, 93 insertions(+), 181 deletions(-)

diff --git a/src/interpreter/plugin/DatePlugin.ts b/src/interpreter/plugin/DatePlugin.ts
index 558a2030e8..e37ac1bcb6 100644
--- a/src/interpreter/plugin/DatePlugin.ts
+++ b/src/interpreter/plugin/DatePlugin.ts
@@ -16,25 +16,65 @@ import {FunctionPlugin} from './FunctionPlugin'
 export class DatePlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DATE': {
-      method: 'date'
+      method: 'date',
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+        ]
+      },
     },
     'MONTH': {
-      method: 'month'
+      method: 'month',
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+        ]
+      },
     },
     'YEAR': {
-      method: 'year'
+      method: 'year',
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+        ]
+      },
     },
     'TEXT': {
-      method: 'text'
+      method: 'text',
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'string'},
+        ]
+      },
     },
     'EOMONTH': {
-      method: 'eomonth'
+      method: 'eomonth',
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+        ]
+      },
     },
     'DAY': {
-      method: 'day'
+      method: 'day',
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+        ]
+      },
     },
     'DAYS': {
-      method: 'days'
+      method: 'days',
+      parameters: {
+        list: [
+          {argumentType: 'number'},
+          {argumentType: 'number'},
+        ]
+      },
     },
   }
 
@@ -47,131 +87,43 @@ export class DatePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public date(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 3) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const year = this.evaluateAst(ast.args[0], formulaAddress)
-    const month = this.evaluateAst(ast.args[1], formulaAddress)
-    const day = this.evaluateAst(ast.args[2], formulaAddress)
-    if (year instanceof SimpleRangeValue || month instanceof SimpleRangeValue || day instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const coercedYear = this.coerceScalarToNumberOrError(year)
-    const coercedMonth = this.coerceScalarToNumberOrError(month)
-    const coercedDay = this.coerceScalarToNumberOrError(day)
-
-    if (coercedYear instanceof CellError) {
-      return coercedYear
-    }
-
-    if (coercedMonth instanceof CellError) {
-      return coercedMonth
-    }
-
-    if (coercedDay instanceof CellError) {
-      return coercedDay
-    }
-    const d = Math.trunc(coercedDay)
-    let m = Math.trunc(coercedMonth)
-    let y = Math.trunc(coercedYear)
-    if (y < this.interpreter.dateHelper.getEpochYearZero()) {
-      y += this.interpreter.dateHelper.getEpochYearZero()
-    }
-    const delta = Math.floor((m - 1) / 12)
-    y += delta
-    m -= delta * 12
-
-    const date = {year: y, month: m, day: 1}
-    if (this.interpreter.dateHelper.isValidDate(date)) {
-      const ret = this.interpreter.dateHelper.dateToNumber(date) + (d - 1)
-      if (this.interpreter.dateHelper.getWithinBounds(ret)) {
-        return ret
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DATE'), (year, month, day) => {
+      const d = Math.trunc(day)
+      let m = Math.trunc(month)
+      let y = Math.trunc(year)
+      if (y < this.interpreter.dateHelper.getEpochYearZero()) {
+        y += this.interpreter.dateHelper.getEpochYearZero()
       }
-    }
-    return new CellError(ErrorType.VALUE)
+      const delta = Math.floor((m - 1) / 12)
+      y += delta
+      m -= delta * 12
+
+      const date = {year: y, month: m, day: 1}
+      if (this.interpreter.dateHelper.isValidDate(date)) {
+        const ret = this.interpreter.dateHelper.dateToNumber(date) + (d - 1)
+        if (this.interpreter.dateHelper.getWithinBounds(ret)) {
+          return ret
+        }
+      }
+      return new CellError(ErrorType.VALUE)
+    })
   }
 
   public eomonth(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const dateNumber = this.coerceScalarToNumberOrError(arg)
-    if (dateNumber instanceof CellError) {
-      return dateNumber
-    }
-
-    const numberOfMonthsToShiftValue = this.evaluateAst(ast.args[1], formulaAddress)
-    if (numberOfMonthsToShiftValue instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const numberOfMonthsToShift = this.coerceScalarToNumberOrError(numberOfMonthsToShiftValue)
-    if (numberOfMonthsToShift instanceof CellError) {
-      return numberOfMonthsToShift
-    }
-
-    const date = this.interpreter.dateHelper.numberToSimpleDate(dateNumber)
-    return this.interpreter.dateHelper.dateToNumber(endOfMonth(offsetMonth(date, numberOfMonthsToShift)))
+    return this.runFunction(ast.args, formulaAddress, this.parameters('EOMONTH'), (dateNumber, numberOfMonthsToShift) => {
+      const date = this.interpreter.dateHelper.numberToSimpleDate(dateNumber)
+      return this.interpreter.dateHelper.dateToNumber(endOfMonth(offsetMonth(date, numberOfMonthsToShift)))
+    })
   }
 
   public day(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const dateNumber = this.coerceScalarToNumberOrError(arg)
-    if (dateNumber instanceof CellError) {
-      return dateNumber
-    }
-    return this.interpreter.dateHelper.numberToSimpleDate(dateNumber).day
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DAY'),
+      (dateNumber) => this.interpreter.dateHelper.numberToSimpleDate(dateNumber).day
+    )
   }
 
   public days(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const endDate = this.evaluateAst(ast.args[0], formulaAddress)
-    if (endDate instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const endDateNumber = this.coerceScalarToNumberOrError(endDate)
-    if (endDateNumber instanceof CellError) {
-      return endDateNumber
-    }
-
-    const startDate = this.evaluateAst(ast.args[1], formulaAddress)
-    if (startDate instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const startDateNumber = this.coerceScalarToNumberOrError(startDate)
-    if (startDateNumber instanceof CellError) {
-      return startDateNumber
-    }
-
-    return endDateNumber - startDateNumber
+    return this.runFunction(ast.args, formulaAddress, this.parameters('DAYS'), (endDate, startDate) => endDate - startDate)
   }
 
   /**
@@ -183,23 +135,9 @@ export class DatePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public month(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const dateNumber = this.coerceScalarToNumberOrError(arg)
-    if (dateNumber instanceof CellError) {
-      return dateNumber
-    }
-
-    return this.interpreter.dateHelper.numberToSimpleDate(dateNumber).month
+    return this.runFunction(ast.args, formulaAddress, this.parameters('MONTH'),
+      (dateNumber) => this.interpreter.dateHelper.numberToSimpleDate(dateNumber).month
+    )
   }
 
   /**
@@ -211,23 +149,9 @@ export class DatePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public year(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 1) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const arg = this.evaluateAst(ast.args[0], formulaAddress)
-    if (arg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const dateNumber = this.coerceScalarToNumberOrError(arg)
-    if (dateNumber instanceof CellError) {
-      return dateNumber
-    }
-
-    return this.interpreter.dateHelper.numberToSimpleDate(dateNumber).year
+    return this.runFunction(ast.args, formulaAddress, this.parameters('YEAR'),
+      (dateNumber) => this.interpreter.dateHelper.numberToSimpleDate(dateNumber).year
+    )
   }
 
   /**
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 76d4a436a2..5afb3cd6a4 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -172,43 +172,31 @@ export abstract class FunctionPlugin {
     const coercedArguments: Maybe<InterpreterValue>[] = []
 
     let argCoerceFailure: Maybe<CellError> = undefined
-    let j = 0
     let i = 0
-    while(i<scalarValues.length || j<argumentDefinitions.length) {
-      if(j===argumentDefinitions.length) {
-        if(functionDefinition.repeatedArg) {
-          j--
-        } else {
-          return new CellError(ErrorType.NA)
-        }
-      }
+    if(!functionDefinition.repeatedArg && argumentDefinitions.length < scalarValues.length) {
+      return new CellError(ErrorType.NA)
+    }
+    for(let i=0; i<Math.max(scalarValues.length, argumentDefinitions.length); i++) {
+      const j = Math.min(i, argumentDefinitions.length-1)
       const [val, ignorable] = scalarValues[i] ?? [undefined, undefined]
       const arg = val ?? argumentDefinitions[j]?.defaultValue
       if(arg === undefined) {
         if(argumentDefinitions[j]?.optionalArg) {
-          i++
-          j++
           coercedArguments.push(undefined)
-          continue
         } else {
           return new CellError(ErrorType.NA)
         }
-      }
-      const coercedArg = val !== undefined ? this.coerceToType(arg, argumentDefinitions[j]) : arg
-      if(coercedArg === undefined) {
-        if(!ignorable) {
+      } else {
+        const coercedArg = val !== undefined ? this.coerceToType(arg, argumentDefinitions[j]) : arg
+        if(coercedArg !== undefined) {
+          if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
+            argCoerceFailure = argCoerceFailure ?? coercedArg
+          }
+          coercedArguments.push(coercedArg)
+        } else if (!ignorable) {
           argCoerceFailure = argCoerceFailure ?? (new CellError(ErrorType.VALUE))
         }
-        i++
-        j++
-        continue
-      }
-      if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
-        argCoerceFailure = argCoerceFailure ?? coercedArg
       }
-      coercedArguments.push(coercedArg)
-      j++
-      i++
     }
 
     return argCoerceFailure ?? fn(...coercedArguments)

From 6ffe1dfb02eb5d3e04e2befe60fbb0d3795a9ddf Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 29 Jul 2020 14:56:25 +0200
Subject: [PATCH 65/97] docs

---
 src/interpreter/plugin/FunctionPlugin.ts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 5afb3cd6a4..bec7d10ffd 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -177,6 +177,8 @@ export abstract class FunctionPlugin {
       return new CellError(ErrorType.NA)
     }
     for(let i=0; i<Math.max(scalarValues.length, argumentDefinitions.length); i++) {
+      // i points to where are we in the scalarValues list,
+      // j points to where are we in the argumentDefinitions list
       const j = Math.min(i, argumentDefinitions.length-1)
       const [val, ignorable] = scalarValues[i] ?? [undefined, undefined]
       const arg = val ?? argumentDefinitions[j]?.defaultValue
@@ -184,16 +186,20 @@ export abstract class FunctionPlugin {
         if(argumentDefinitions[j]?.optionalArg) {
           coercedArguments.push(undefined)
         } else {
+          //not enough values passed as arguments, and there was no default value and argument was not optional
           return new CellError(ErrorType.NA)
         }
       } else {
+        //we apply coerce only to non-default values
         const coercedArg = val !== undefined ? this.coerceToType(arg, argumentDefinitions[j]) : arg
         if(coercedArg !== undefined) {
           if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
+            //if this is first error encountered, store it
             argCoerceFailure = argCoerceFailure ?? coercedArg
           }
           coercedArguments.push(coercedArg)
         } else if (!ignorable) {
+          //if this is first error encountered, store it
           argCoerceFailure = argCoerceFailure ?? (new CellError(ErrorType.VALUE))
         }
       }

From e43ac24e6ed45451c27c1726a3b0fa1e31d76d4b Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 29 Jul 2020 15:03:00 +0200
Subject: [PATCH 66/97] linter

---
 src/interpreter/plugin/FunctionPlugin.ts |  1 -
 test/performance/1-basic.ts              | 23 +++++++++++------------
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index bec7d10ffd..14235e3558 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -172,7 +172,6 @@ export abstract class FunctionPlugin {
     const coercedArguments: Maybe<InterpreterValue>[] = []
 
     let argCoerceFailure: Maybe<CellError> = undefined
-    let i = 0
     if(!functionDefinition.repeatedArg && argumentDefinitions.length < scalarValues.length) {
       return new CellError(ErrorType.NA)
     }
diff --git a/test/performance/1-basic.ts b/test/performance/1-basic.ts
index ec72d88dfc..e494e7db4a 100644
--- a/test/performance/1-basic.ts
+++ b/test/performance/1-basic.ts
@@ -2,24 +2,23 @@ import {batch, benchmark, BenchmarkResult} from './benchmark'
 import {expectedValues as expectedValuesT, sheet as sheetTGenerator} from './sheets/05-sheet-t'
 import {expectedValues as expectedValuesA, sheet as sheetAGenerator} from './sheets/09-sheet-a'
 import {expectedValues as expectedValuesB, sheet as sheetBGenerator} from './sheets/10-sheet-b'
-import {sheet as median} from './sheets/median-evaluation'
 import {sheet as columnRangesGenerator} from './sheets/column-ranges'
 
 (() => {
-  // const sheetA = sheetAGenerator()
-  // const sheetB = sheetBGenerator()
-  // const sheetT = sheetTGenerator()
-  // const infiniteRanges = columnRangesGenerator()
+  const sheetA = sheetAGenerator()
+  const sheetB = sheetBGenerator()
+  const sheetT = sheetTGenerator()
+  const infiniteRanges = columnRangesGenerator()
 
   const result: BenchmarkResult[] = []
   batch(result,
-    () => benchmark('Sheet A', median(), [], {numberOfRuns: 10}),
-    // () => benchmark('Sheet B', sheetB, expectedValuesB(sheetB), {numberOfRuns: 10}),
-    // () => benchmark('Sheet T', sheetT, expectedValuesT(sheetT), {numberOfRuns: 10}),
-    // () => benchmark('Column ranges', infiniteRanges, [{
-    //   address: 'AX50',
-    //   value: 1.04519967355127e+63
-    // }], {expectedTime: 1000, numberOfRuns: 10})
+    () => benchmark('Sheet A', sheetA, expectedValuesA(sheetA), {numberOfRuns: 10}),
+    () => benchmark('Sheet B', sheetB, expectedValuesB(sheetB), {numberOfRuns: 10}),
+    () => benchmark('Sheet T', sheetT, expectedValuesT(sheetT), {numberOfRuns: 10}),
+    () => benchmark('Column ranges', infiniteRanges, [{
+      address: 'AX50',
+      value: 1.04519967355127e+63
+    }], {expectedTime: 1000, numberOfRuns: 10})
   )
 
   console.table(result.map(e => ({

From 3e1e6d2688e3a2e861803f2c3dd53951844b5dd8 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 29 Jul 2020 15:53:27 +0200
Subject: [PATCH 67/97] fixed tests

---
 test/optional-parameters.spec.ts | 63 ++++++++++++++++----------------
 1 file changed, 32 insertions(+), 31 deletions(-)

diff --git a/test/optional-parameters.spec.ts b/test/optional-parameters.spec.ts
index bc29db26e2..b2d0800d15 100644
--- a/test/optional-parameters.spec.ts
+++ b/test/optional-parameters.spec.ts
@@ -10,32 +10,19 @@ class FooPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'FOO': {
       method: 'foo',
+      parameters: {
+        list: [
+          { argumentType: 'string', defaultValue: 'default1'},
+          { argumentType: 'string', defaultValue: 'default2'},
+        ],
+      },
     },
   }
 
   public foo(ast: ProcedureAst, formulaAddress: SimpleCellAddress) {
-    if (ast.args.length > 2) {
-      return new CellError(ErrorType.NA)
-    }
-
-    const arg1 = ast.args[0].type !== AstNodeType.EMPTY ? this.evaluateAst(ast.args[0], formulaAddress) : 'default1'
-    if (arg1 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-    const arg2 = ast.args[1].type !== AstNodeType.EMPTY ? this.evaluateAst(ast.args[1], formulaAddress) : 'default2'
-    if (arg2 instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const coercedArg1 = coerceScalarToString(arg1)
-    if (coercedArg1 instanceof CellError)  {
-      return coercedArg1
-    }
-    const coercedArg2 = coerceScalarToString(arg2)
-    if (coercedArg2 instanceof CellError) {
-      return coercedArg2
-    }
-    return coercedArg1 + '+' + coercedArg2
+    return this.runFunction(ast.args, formulaAddress, this.parameters('FOO'),
+      (arg1, arg2) => arg1+'+'+arg2
+    )
   }
 }
 
@@ -48,24 +35,38 @@ describe('Nonexistent parameters', () => {
       ['=foo( ,2)'],
       ['=foo(1,)'],
       ['=foo( , )'],
+      ['=foo(1)'],
+      ['=foo()'],
     ], {functionPlugins: [FooPlugin]})
 
     expect(engine.getCellValue(adr('A1'))).toBe('1+2')
-    expect(engine.getCellValue(adr('A2'))).toBe('default1+2')
-    expect(engine.getCellValue(adr('A3'))).toBe('default1+2')
-    expect(engine.getCellValue(adr('A4'))).toBe('1+default2')
-    expect(engine.getCellValue(adr('A5'))).toBe('default1+default2')
+    expect(engine.getCellValue(adr('A2'))).toBe('+2')
+    expect(engine.getCellValue(adr('A3'))).toBe('+2')
+    expect(engine.getCellValue(adr('A4'))).toBe('1+')
+    expect(engine.getCellValue(adr('A5'))).toBe('+')
+    expect(engine.getCellValue(adr('A6'))).toBe('1+default2')
+    expect(engine.getCellValue(adr('A7'))).toBe('default1+default2')
   })
 
-  it('typical function do not accept', () => {
+  it('log fails with coerce to 0', () => {
     const engine = HyperFormula.buildFromArray([
-      ['=DATE(,1,1900)'],
       ['=LOG(10,)'],
-      ['=SUM(,1)']
     ])
 
     expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NUM))
-    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NUM))
-    expect(engine.getCellValue(adr('A3'))).toEqual(detailedError(ErrorType.NUM))
   })
+
+  it('other function coerce EmptyValue', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=DATE(,1,1900)'],
+      ['=SUM(,1)'],
+      ['=CONCATENATE(,"abcd")']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1901)
+    expect(engine.getCellValue(adr('A2'))).toEqual(detailedError(ErrorType.NUM)) //TODO when SUM() is fixed, it should evaluate to 1
+    expect(engine.getCellValue(adr('A3'))).toEqual('abcd')
+  })
+
+
 })

From 25706ff2a5224b6e913e33fd06f76d579528af86 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 29 Jul 2020 16:20:44 +0200
Subject: [PATCH 68/97] function text fixed

---
 src/interpreter/plugin/DatePlugin.ts   | 26 +++-----------------------
 test/interpreter/function-text.spec.ts |  4 +++-
 2 files changed, 6 insertions(+), 24 deletions(-)

diff --git a/src/interpreter/plugin/DatePlugin.ts b/src/interpreter/plugin/DatePlugin.ts
index e37ac1bcb6..ef17248886 100644
--- a/src/interpreter/plugin/DatePlugin.ts
+++ b/src/interpreter/plugin/DatePlugin.ts
@@ -163,28 +163,8 @@ export class DatePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public text(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 2) {
-      return new CellError(ErrorType.NA)
-    }
-    if (ast.args.some((ast) => ast.type === AstNodeType.EMPTY)) {
-      return new CellError(ErrorType.NUM)
-    }
-
-    const dateArg = this.evaluateAst(ast.args[0], formulaAddress)
-    const formatArg = this.evaluateAst(ast.args[1], formulaAddress)
-    if (dateArg instanceof SimpleRangeValue) {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    const numberRepresentation = this.coerceScalarToNumberOrError(dateArg)
-    if (numberRepresentation instanceof CellError) {
-      return numberRepresentation
-    }
-
-    if (typeof formatArg !== 'string') {
-      return new CellError(ErrorType.VALUE)
-    }
-
-    return format(numberRepresentation, formatArg, this.config, this.interpreter.dateHelper)
+    return this.runFunction(ast.args, formulaAddress, this.parameters('TEXT'),
+      (numberRepresentation, formatArg) =>format(numberRepresentation, formatArg, this.config, this.interpreter.dateHelper)
+    )
   }
 }
diff --git a/test/interpreter/function-text.spec.ts b/test/interpreter/function-text.spec.ts
index 7257ba2da5..fcf6ded58f 100644
--- a/test/interpreter/function-text.spec.ts
+++ b/test/interpreter/function-text.spec.ts
@@ -26,9 +26,11 @@ describe('Text', () => {
   it('wrong format argument',  () => {
     const engine =  HyperFormula.buildFromArray([
       ['=TEXT(2, 42)'],
+      ['=TEXT(2, 0)'],
     ])
 
-    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('A1'))).toEqual("42")
+    expect(engine.getCellValue(adr('A2'))).toEqual("2")
   })
 
   it('wrong date argument',  () => {

From b4d8fdf34e267a3f18083c418eebf254665630e9 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 29 Jul 2020 16:24:03 +0200
Subject: [PATCH 69/97] linter

---
 test/interpreter/function-text.spec.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/interpreter/function-text.spec.ts b/test/interpreter/function-text.spec.ts
index fcf6ded58f..5385fb6826 100644
--- a/test/interpreter/function-text.spec.ts
+++ b/test/interpreter/function-text.spec.ts
@@ -29,8 +29,8 @@ describe('Text', () => {
       ['=TEXT(2, 0)'],
     ])
 
-    expect(engine.getCellValue(adr('A1'))).toEqual("42")
-    expect(engine.getCellValue(adr('A2'))).toEqual("2")
+    expect(engine.getCellValue(adr('A1'))).toEqual('42')
+    expect(engine.getCellValue(adr('A2'))).toEqual('2')
   })
 
   it('wrong date argument',  () => {

From dfb152fb050d5aa21f04ec6cc6bec0309519c1cc Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Wed, 29 Jul 2020 18:47:48 +0200
Subject: [PATCH 70/97] type unification

---
 src/Cell.ts                                   |  5 ++--
 src/CellValue.ts                              |  6 ++---
 src/ColumnSearch/ColumnIndex.ts               | 25 +++++++++----------
 src/ColumnSearch/ColumnSearchStrategy.ts      | 11 ++++----
 src/ContentChanges.ts                         |  9 ++++---
 .../AddressMapping/AddressMapping.ts          |  5 ++--
 src/DependencyGraph/DependencyGraph.ts        |  5 ++--
 src/DependencyGraph/FormulaCellVertex.ts      | 11 ++++----
 src/Evaluator.ts                              |  8 +++---
 src/interpreter/ArithmeticHelper.ts           |  6 ++---
 src/interpreter/plugin/InformationPlugin.ts   |  5 ++--
 src/interpreter/plugin/VersionPlugin.ts       |  4 +--
 src/interpreter/plugin/VlookupPlugin.ts       |  5 ++--
 test/interpreter/function-version.spec.ts     |  4 +--
 14 files changed, 55 insertions(+), 54 deletions(-)

diff --git a/src/Cell.ts b/src/Cell.ts
index 5340f66e96..190c9e132e 100644
--- a/src/Cell.ts
+++ b/src/Cell.ts
@@ -6,7 +6,7 @@
 import {CellVertex, FormulaCellVertex, MatrixVertex, ParsingErrorVertex, ValueCellVertex} from './DependencyGraph'
 import {CellAddress} from './parser'
 import {AddressWithSheet} from './parser/Address'
-import {SimpleRangeValue} from './interpreter/InterpreterValue'
+import {InterpreterValue, SimpleRangeValue} from './interpreter/InterpreterValue'
 
 /**
  * Possible errors returned by our interpreter.
@@ -35,7 +35,6 @@ export const EmptyValue = Symbol('Empty value')
 export type EmptyValueType = typeof EmptyValue
 export type InternalNoErrorCellValue = number | string | boolean | EmptyValueType
 export type InternalScalarValue = InternalNoErrorCellValue | CellError
-export type InternalCellValue = InternalScalarValue | SimpleRangeValue
 
 export enum CellType {
   FORMULA = 'FORMULA',
@@ -82,7 +81,7 @@ export const CellValueTypeOrd = (arg: CellValueType): number => {
   }
 }
 
-export const getCellValueType = (cellValue: InternalCellValue): CellValueType => {
+export const getCellValueType = (cellValue: InterpreterValue): CellValueType => {
   if (cellValue === EmptyValue) {
     return CellValueType.EMPTY
   }
diff --git a/src/CellValue.ts b/src/CellValue.ts
index b0c1e5cabc..00cdb2c858 100644
--- a/src/CellValue.ts
+++ b/src/CellValue.ts
@@ -3,11 +3,11 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {CellError, EmptyValue, ErrorType, InternalCellValue, simpleCellAddress, SimpleCellAddress} from './Cell'
+import {CellError, EmptyValue, ErrorType, simpleCellAddress, SimpleCellAddress} from './Cell'
 import {Config} from './Config'
 import {CellValueChange} from './ContentChanges'
 import {NamedExpressions} from './NamedExpressions'
-import {SimpleRangeValue} from './interpreter/InterpreterValue'
+import {InterpreterValue, SimpleRangeValue} from './interpreter/InterpreterValue'
 
 export type NoErrorCellValue = number | string | boolean | null
 export type CellValue = NoErrorCellValue | DetailedCellError
@@ -87,7 +87,7 @@ export class Exporter {
     }
   }
 
-  public exportValue(value: InternalCellValue): CellValue {
+  public exportValue(value: InterpreterValue): CellValue {
     if (value instanceof SimpleRangeValue) {
       return this.detailedError(new CellError(ErrorType.VALUE))
     } else if (this.config.smartRounding && typeof value == 'number') {
diff --git a/src/ColumnSearch/ColumnIndex.ts b/src/ColumnSearch/ColumnIndex.ts
index 6c8aa349ab..af2dd3dad9 100644
--- a/src/ColumnSearch/ColumnIndex.ts
+++ b/src/ColumnSearch/ColumnIndex.ts
@@ -6,7 +6,6 @@
 import {AbsoluteCellRange} from '../AbsoluteCellRange'
 import {
   CellError,
-  InternalCellValue,
   InternalNoErrorCellValue,
   InternalScalarValue,
   movedSimpleCellAddress,
@@ -23,9 +22,9 @@ import {ColumnSearchStrategy} from './ColumnSearchStrategy'
 import {AddRowsTransformer} from '../dependencyTransformers/AddRowsTransformer'
 import {RemoveRowsTransformer} from '../dependencyTransformers/RemoveRowsTransformer'
 import {FormulaTransformer} from '../dependencyTransformers/Transformer'
-import {SimpleRangeValue} from '../interpreter/InterpreterValue'
+import {InterpreterValue, SimpleRangeValue} from '../interpreter/InterpreterValue'
 
-type ColumnMap = Map<InternalCellValue, ValueIndex>
+type ColumnMap = Map<InterpreterValue, ValueIndex>
 
 interface ValueIndex {
   version: number,
@@ -49,7 +48,7 @@ export class ColumnIndex implements ColumnSearchStrategy {
     this.binarySearchStrategy = new ColumnBinarySearch(dependencyGraph, config)
   }
 
-  public add(value: InternalCellValue | Matrix, address: SimpleCellAddress) {
+  public add(value: InterpreterValue | Matrix, address: SimpleCellAddress) {
     if (value instanceof Matrix) {
       for (const [matrixValue, cellAddress] of value.generateValues(address)) {
         this.addSingleCellValue(matrixValue, cellAddress)
@@ -59,7 +58,7 @@ export class ColumnIndex implements ColumnSearchStrategy {
     }
   }
 
-  public remove(value: InternalCellValue | Matrix | null, address: SimpleCellAddress) {
+  public remove(value: InterpreterValue | Matrix | null, address: SimpleCellAddress) {
     if (!value) {
       return
     }
@@ -73,7 +72,7 @@ export class ColumnIndex implements ColumnSearchStrategy {
     }
   }
 
-  public change(oldValue: InternalCellValue | Matrix | null, newValue: InternalScalarValue | Matrix, address: SimpleCellAddress) {
+  public change(oldValue: InterpreterValue | Matrix | null, newValue: InternalScalarValue | Matrix, address: SimpleCellAddress) {
     if (oldValue === newValue) {
       return
     }
@@ -113,7 +112,7 @@ export class ColumnIndex implements ColumnSearchStrategy {
     return rowNumber <= range.end.row ? rowNumber : this.binarySearchStrategy.find(key, range, sorted)
   }
 
-  public advancedFind(keyMatcher: (arg: InternalCellValue) => boolean, range: AbsoluteCellRange): number {
+  public advancedFind(keyMatcher: (arg: InterpreterValue) => boolean, range: AbsoluteCellRange): number {
     return this.binarySearchStrategy.advancedFind(keyMatcher, range)
   }
 
@@ -154,7 +153,7 @@ export class ColumnIndex implements ColumnSearchStrategy {
     return columnMap
   }
 
-  public getValueIndex(sheet: number, col: number, value: InternalCellValue): ValueIndex {
+  public getValueIndex(sheet: number, col: number, value: InterpreterValue): ValueIndex {
     const columnMap = this.getColumnMap(sheet, col)
     let index = this.getColumnMap(sheet, col).get(value)
     if (!index) {
@@ -167,7 +166,7 @@ export class ColumnIndex implements ColumnSearchStrategy {
     return index
   }
 
-  public ensureRecentData(sheet: number, col: number, value: InternalCellValue) {
+  public ensureRecentData(sheet: number, col: number, value: InterpreterValue) {
     const valueIndex = this.getValueIndex(sheet, col, value)
     const actualVersion = this.transformingService.version()
     if (valueIndex.version === actualVersion) {
@@ -190,7 +189,7 @@ export class ColumnIndex implements ColumnSearchStrategy {
     this.index.clear()
   }
 
-  private addSingleCellValue(value: InternalCellValue, address: SimpleCellAddress) {
+  private addSingleCellValue(value: InterpreterValue, address: SimpleCellAddress) {
     this.stats.measure(StatType.BUILD_COLUMN_INDEX, () => {
       this.ensureRecentData(address.sheet, address.col, value)
       const valueIndex = this.getValueIndex(address.sheet, address.col, value)
@@ -198,7 +197,7 @@ export class ColumnIndex implements ColumnSearchStrategy {
     })
   }
 
-  private removeSingleValue(value: InternalCellValue, address: SimpleCellAddress) {
+  private removeSingleValue(value: InterpreterValue, address: SimpleCellAddress) {
     this.stats.measure(StatType.BUILD_COLUMN_INDEX, () => {
       this.ensureRecentData(address.sheet, address.col, value)
 
@@ -221,12 +220,12 @@ export class ColumnIndex implements ColumnSearchStrategy {
     })
   }
 
-  private addRows(col: number, rowsSpan: RowsSpan, value: InternalCellValue) {
+  private addRows(col: number, rowsSpan: RowsSpan, value: InterpreterValue) {
     const valueIndex = this.getValueIndex(rowsSpan.sheet, col, value)
     this.shiftRows(valueIndex, rowsSpan.rowStart, rowsSpan.numberOfRows)
   }
 
-  private removeRows(col: number, rowsSpan: RowsSpan, value: InternalCellValue) {
+  private removeRows(col: number, rowsSpan: RowsSpan, value: InterpreterValue) {
     const valueIndex = this.getValueIndex(rowsSpan.sheet, col, value)
     this.removeRowsFromValues(valueIndex, rowsSpan)
     this.shiftRows(valueIndex, rowsSpan.rowEnd + 1, -rowsSpan.numberOfRows)
diff --git a/src/ColumnSearch/ColumnSearchStrategy.ts b/src/ColumnSearch/ColumnSearchStrategy.ts
index 0450f0f963..8ba663889b 100644
--- a/src/ColumnSearch/ColumnSearchStrategy.ts
+++ b/src/ColumnSearch/ColumnSearchStrategy.ts
@@ -4,9 +4,10 @@
  */
 
 import {AbsoluteCellRange} from '../AbsoluteCellRange'
-import {InternalCellValue, InternalNoErrorCellValue, InternalScalarValue, SimpleCellAddress} from '../Cell'
+import {InternalNoErrorCellValue, InternalScalarValue, SimpleCellAddress} from '../Cell'
 import {Config} from '../Config'
 import {DependencyGraph} from '../DependencyGraph'
+import {InterpreterValue} from '../interpreter/InterpreterValue'
 import {Matrix} from '../Matrix'
 import {Statistics} from '../statistics/Statistics'
 import {ColumnBinarySearch} from './ColumnBinarySearch'
@@ -14,11 +15,11 @@ import {ColumnIndex} from './ColumnIndex'
 import {ColumnsSpan} from '../Span'
 
 export interface ColumnSearchStrategy {
-  add(value: InternalCellValue | Matrix, address: SimpleCellAddress): void,
+  add(value: InterpreterValue | Matrix, address: SimpleCellAddress): void,
 
-  remove(value: InternalCellValue | Matrix | null, address: SimpleCellAddress): void,
+  remove(value: InterpreterValue | Matrix | null, address: SimpleCellAddress): void,
 
-  change(oldValue: InternalCellValue | Matrix | null, newValue: InternalCellValue | Matrix, address: SimpleCellAddress): void,
+  change(oldValue: InterpreterValue | Matrix | null, newValue: InterpreterValue | Matrix, address: SimpleCellAddress): void,
 
   addColumns(columnsSpan: ColumnsSpan): void,
 
@@ -32,7 +33,7 @@ export interface ColumnSearchStrategy {
 
   find(key: InternalNoErrorCellValue, range: AbsoluteCellRange, sorted: boolean): number,
 
-  advancedFind(keyMatcher: (arg: InternalCellValue) => boolean, range: AbsoluteCellRange): number,
+  advancedFind(keyMatcher: (arg: InterpreterValue) => boolean, range: AbsoluteCellRange): number,
 
   destroy(): void,
 }
diff --git a/src/ContentChanges.ts b/src/ContentChanges.ts
index 3d5e289827..db0f5d3d92 100644
--- a/src/ContentChanges.ts
+++ b/src/ContentChanges.ts
@@ -3,14 +3,15 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {InternalCellValue, SimpleCellAddress} from './Cell'
+import {SimpleCellAddress} from './Cell'
+import {InterpreterValue} from './interpreter/InterpreterValue'
 import {Matrix} from './Matrix'
 
 export interface CellValueChange {
   sheet: number,
   row: number,
   col: number,
-  value: InternalCellValue,
+  value: InterpreterValue,
 }
 
 export interface ChangeExporter<T> {
@@ -37,7 +38,7 @@ export class ContentChanges {
     }
   }
 
-  public addChange(newValue: InternalCellValue, address: SimpleCellAddress): void {
+  public addChange(newValue: InterpreterValue, address: SimpleCellAddress): void {
     this.addSingleCellValue(newValue, address)
   }
 
@@ -61,7 +62,7 @@ export class ContentChanges {
     return this.changes === []
   }
 
-  private addSingleCellValue(value: InternalCellValue, address: SimpleCellAddress) {
+  private addSingleCellValue(value: InterpreterValue, address: SimpleCellAddress) {
     this.add({
       sheet: address.sheet,
       col: address.col,
diff --git a/src/DependencyGraph/AddressMapping/AddressMapping.ts b/src/DependencyGraph/AddressMapping/AddressMapping.ts
index d938e48287..c25c88a1d3 100644
--- a/src/DependencyGraph/AddressMapping/AddressMapping.ts
+++ b/src/DependencyGraph/AddressMapping/AddressMapping.ts
@@ -3,7 +3,8 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {EmptyValue, InternalCellValue, SimpleCellAddress} from '../../Cell'
+import {EmptyValue, SimpleCellAddress} from '../../Cell'
+import {InterpreterValue} from '../../interpreter/InterpreterValue'
 import {ColumnsSpan, RowsSpan} from '../../Span'
 import {MatrixVertex} from '../index'
 import {CellVertex} from '../Vertex'
@@ -64,7 +65,7 @@ export class AddressMapping {
     this.addSheet(sheetId, new strategyConstructor(width, height))
   }
 
-  public getCellValue(address: SimpleCellAddress): InternalCellValue {
+  public getCellValue(address: SimpleCellAddress): InterpreterValue {
     const vertex = this.getCell(address)
 
     if (vertex === null) {
diff --git a/src/DependencyGraph/DependencyGraph.ts b/src/DependencyGraph/DependencyGraph.ts
index 0b2885deb9..c556644e2b 100644
--- a/src/DependencyGraph/DependencyGraph.ts
+++ b/src/DependencyGraph/DependencyGraph.ts
@@ -10,7 +10,6 @@ import {
   CellError,
   EmptyValue,
   ErrorType,
-  InternalCellValue,
   InternalScalarValue,
   simpleCellAddress,
   SimpleCellAddress
@@ -42,7 +41,7 @@ import {RangeMapping} from './RangeMapping'
 import {SheetMapping} from './SheetMapping'
 import {ValueCellVertexValue} from './ValueCellVertex'
 import {FunctionRegistry} from '../interpreter/FunctionRegistry'
-import {SimpleRangeValue} from '../interpreter/InterpreterValue'
+import {InterpreterValue, SimpleRangeValue} from '../interpreter/InterpreterValue'
 
 export class DependencyGraph {
   /*
@@ -597,7 +596,7 @@ export class DependencyGraph {
     return this.addressMapping.getCell(address)
   }
 
-  public getCellValue(address: SimpleCellAddress): InternalCellValue {
+  public getCellValue(address: SimpleCellAddress): InterpreterValue {
     return this.addressMapping.getCellValue(address)
   }
 
diff --git a/src/DependencyGraph/FormulaCellVertex.ts b/src/DependencyGraph/FormulaCellVertex.ts
index 8af673cd72..45979e2d65 100644
--- a/src/DependencyGraph/FormulaCellVertex.ts
+++ b/src/DependencyGraph/FormulaCellVertex.ts
@@ -3,7 +3,8 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {InternalCellValue, SimpleCellAddress} from '../Cell'
+import {SimpleCellAddress} from '../Cell'
+import {InterpreterValue} from '../interpreter/InterpreterValue'
 import {LazilyTransformingAstService} from '../LazilyTransformingAstService'
 import {Ast} from '../parser'
 
@@ -12,7 +13,7 @@ import {Ast} from '../parser'
  */
 export class FormulaCellVertex {
   /** Most recently computed value of this formula. */
-  private cachedCellValue: InternalCellValue | null
+  private cachedCellValue: InterpreterValue | null
 
   constructor(
     /** Formula in AST format */
@@ -60,14 +61,14 @@ export class FormulaCellVertex {
   /**
    * Sets computed cell value stored in this vertex
    */
-  public setCellValue(cellValue: InternalCellValue) {
+  public setCellValue(cellValue: InterpreterValue) {
     this.cachedCellValue = cellValue
   }
 
   /**
    * Returns cell value stored in vertex
    */
-  public getCellValue(): InternalCellValue {
+  public getCellValue(): InterpreterValue {
     if (this.cachedCellValue !== null) {
       return this.cachedCellValue
     } else {
@@ -75,7 +76,7 @@ export class FormulaCellVertex {
     }
   }
 
-  public valueOrNull(): InternalCellValue | null {
+  public valueOrNull(): InterpreterValue | null {
     return this.cachedCellValue
   }
 
diff --git a/src/Evaluator.ts b/src/Evaluator.ts
index 9e1e5079d0..8011a8a401 100644
--- a/src/Evaluator.ts
+++ b/src/Evaluator.ts
@@ -5,7 +5,7 @@
 
 import {AbsoluteCellRange} from './AbsoluteCellRange'
 import {absolutizeDependencies} from './absolutizeDependencies'
-import {CellError, ErrorType, InternalCellValue, SimpleCellAddress} from './Cell'
+import {CellError, ErrorType, SimpleCellAddress} from './Cell'
 import {ColumnSearchStrategy} from './ColumnSearch/ColumnSearchStrategy'
 import {Config} from './Config'
 import {ContentChanges} from './ContentChanges'
@@ -13,7 +13,7 @@ import {DateTimeHelper} from './DateTimeHelper'
 import {DependencyGraph, FormulaCellVertex, MatrixVertex, RangeVertex, Vertex} from './DependencyGraph'
 import {fixNegativeZero, isNumberOverflow} from './interpreter/ArithmeticHelper'
 import {Interpreter} from './interpreter/Interpreter'
-import {SimpleRangeValue} from './interpreter/InterpreterValue'
+import {InterpreterValue, SimpleRangeValue} from './interpreter/InterpreterValue'
 import {Matrix} from './Matrix'
 import {Ast, RelativeDependency} from './parser'
 import {Statistics, StatType} from './statistics'
@@ -110,7 +110,7 @@ export class Evaluator {
     this.interpreter.destroy()
   }
 
-  public runAndForget(ast: Ast, address: SimpleCellAddress, dependencies: RelativeDependency[]): InternalCellValue {
+  public runAndForget(ast: Ast, address: SimpleCellAddress, dependencies: RelativeDependency[]): InterpreterValue {
     const tmpRanges: RangeVertex[] = []
     for (const dep of absolutizeDependencies(dependencies, address)) {
       if (dep instanceof AbsoluteCellRange) {
@@ -165,7 +165,7 @@ export class Evaluator {
     })
   }
 
-  private evaluateAstToCellValue(ast: Ast, formulaAddress: SimpleCellAddress): InternalCellValue {
+  private evaluateAstToCellValue(ast: Ast, formulaAddress: SimpleCellAddress): InterpreterValue {
     const interpreterValue = this.interpreter.evaluateAst(ast, formulaAddress)
     if (interpreterValue instanceof SimpleRangeValue) {
       return interpreterValue
diff --git a/src/interpreter/ArithmeticHelper.ts b/src/interpreter/ArithmeticHelper.ts
index 08fb88e222..c80b4fe649 100644
--- a/src/interpreter/ArithmeticHelper.ts
+++ b/src/interpreter/ArithmeticHelper.ts
@@ -8,7 +8,7 @@ import {
   CellValueTypeOrd,
   EmptyValue,
   ErrorType,
-  getCellValueType, InternalCellValue,
+  getCellValueType,
   InternalNoErrorCellValue,
   InternalScalarValue
 } from '../Cell'
@@ -32,12 +32,12 @@ export class ArithmeticHelper {
     this.actualEps = config.smartRounding ? config.precisionEpsilon : 0
   }
 
-  public eqMatcherFunction(pattern: string): (arg: InternalCellValue) => boolean {
+  public eqMatcherFunction(pattern: string): (arg: InterpreterValue) => boolean {
     const regexp = this.buildRegex(pattern)
     return (cellValue) => (typeof cellValue === 'string' && regexp.test(this.normalizeString(cellValue)))
   }
 
-  public neqMatcherFunction(pattern: string): (arg: InternalCellValue) => boolean {
+  public neqMatcherFunction(pattern: string): (arg: InterpreterValue) => boolean {
     const regexp = this.buildRegex(pattern)
     return (cellValue) => {
       return (typeof cellValue !== 'string' || !regexp.test(this.normalizeString(cellValue)))
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 390e0694fd..ff5f4a1049 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -4,8 +4,9 @@
  */
 
 import {AbsoluteCellRange} from '../../AbsoluteCellRange'
-import {CellError, EmptyValue, ErrorType, InternalCellValue, InternalScalarValue, SimpleCellAddress} from '../../Cell'
+import {CellError, EmptyValue, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {AstNodeType, ProcedureAst} from '../../parser'
+import {InterpreterValue} from '../InterpreterValue'
 import {FunctionPlugin} from './FunctionPlugin'
 
 /**
@@ -195,7 +196,7 @@ export class InformationPlugin extends FunctionPlugin {
     }
   }
 
-  public index(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalCellValue {
+  public index(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InterpreterValue {
     const rangeArg = ast.args[0]
     if (ast.args.length < 1 || ast.args.length > 3) {
       return new CellError(ErrorType.NA)
diff --git a/src/interpreter/plugin/VersionPlugin.ts b/src/interpreter/plugin/VersionPlugin.ts
index e0a829104c..48dc882d91 100644
--- a/src/interpreter/plugin/VersionPlugin.ts
+++ b/src/interpreter/plugin/VersionPlugin.ts
@@ -3,7 +3,7 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import { InternalCellValue } from '../../Cell'
+import {InterpreterValue} from '../InterpreterValue'
 import { FunctionPlugin } from './FunctionPlugin'
 import { HyperFormula } from '../../HyperFormula'
 import { LicenseKeyValidityState } from '../../helpers/licenseKeyValidator'
@@ -23,7 +23,7 @@ export class VersionPlugin extends FunctionPlugin {
     },
   }
 
-  public version(): InternalCellValue {
+  public version(): InterpreterValue {
     const {
       licenseKeyValidityState: validityState,
       licenseKey,
diff --git a/src/interpreter/plugin/VlookupPlugin.ts b/src/interpreter/plugin/VlookupPlugin.ts
index 74372d5e37..b25be12985 100644
--- a/src/interpreter/plugin/VlookupPlugin.ts
+++ b/src/interpreter/plugin/VlookupPlugin.ts
@@ -7,7 +7,6 @@ import {AbsoluteCellRange} from '../../AbsoluteCellRange'
 import {
   CellError,
   ErrorType,
-  InternalCellValue,
   InternalScalarValue,
   simpleCellAddress,
   SimpleCellAddress
@@ -33,7 +32,7 @@ export class VlookupPlugin extends FunctionPlugin {
    * @param ast
    * @param formulaAddress
    */
-  public vlookup(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalCellValue {
+  public vlookup(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InterpreterValue {
     if (ast.args.length < 3 || ast.args.length > 4) {
       return new CellError(ErrorType.NA)
     }
@@ -130,7 +129,7 @@ export class VlookupPlugin extends FunctionPlugin {
     }
   }
 
-  private doVlookup(key: any, range: AbsoluteCellRange, index: number, sorted: boolean): InternalCellValue {
+  private doVlookup(key: any, range: AbsoluteCellRange, index: number, sorted: boolean): InterpreterValue {
     this.dependencyGraph.stats.start(StatType.VLOOKUP)
 
     const searchedRange = AbsoluteCellRange.spanFrom(range.start, 1, range.height())
diff --git a/test/interpreter/function-version.spec.ts b/test/interpreter/function-version.spec.ts
index 1403051f6c..52b85e1789 100644
--- a/test/interpreter/function-version.spec.ts
+++ b/test/interpreter/function-version.spec.ts
@@ -1,5 +1,5 @@
+import {InterpreterValue} from '../../src/interpreter/InterpreterValue'
 import { FunctionPlugin } from '../../src/interpreter/plugin/FunctionPlugin'
-import { InternalCellValue } from '../../src/Cell'
 import { HyperFormula } from '../../src'
 import { adr } from '../testUtils'
 import {ProtectedFunctionError} from '../../src/errors'
@@ -75,7 +75,7 @@ describe('Function VERSION', () => {
         }
       }
     
-      public version(): InternalCellValue {
+      public version(): InterpreterValue {
         return 'version'
       }
     }

From 4ddac2dbd59deaceeef721e1c5c78e1cde7fd8fd Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 24 Jul 2020 12:47:33 +0200
Subject: [PATCH 71/97] Function ISERR

---
 docs/guide/built-in-functions.md            |  3 +-
 src/i18n/languages/csCZ.ts                  |  1 +
 src/i18n/languages/daDK.ts                  |  1 +
 src/i18n/languages/deDE.ts                  |  1 +
 src/i18n/languages/enGB.ts                  |  1 +
 src/i18n/languages/esES.ts                  |  1 +
 src/i18n/languages/fiFI.ts                  |  1 +
 src/i18n/languages/frFR.ts                  |  1 +
 src/i18n/languages/huHU.ts                  |  1 +
 src/i18n/languages/itIT.ts                  |  1 +
 src/i18n/languages/nbNO.ts                  |  1 +
 src/i18n/languages/nlNL.ts                  |  1 +
 src/i18n/languages/plPL.ts                  |  1 +
 src/i18n/languages/ptPT.ts                  |  1 +
 src/i18n/languages/ruRU.ts                  |  1 +
 src/i18n/languages/svSE.ts                  |  1 +
 src/i18n/languages/trTR.ts                  |  1 +
 src/interpreter/plugin/InformationPlugin.ts | 73 +++++++++++++++------
 test/interpreter/function-iserr.spec.ts     | 52 +++++++++++++++
 19 files changed, 124 insertions(+), 20 deletions(-)
 create mode 100644 test/interpreter/function-iserr.spec.ts

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index ae88cded97..54bebc414f 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -82,7 +82,8 @@ lets you design your own [custom functions](custom-functions).
 | ERF | Engineering | Returns values of the Gaussian error integral. | ERF(Lower_Limit; Upper_Limit) |
 | ERFC | Engineering | Returns complementary values of the Gaussian error integral between x and infinity. | ERFC(Lower_Limit) |
 | ISBLANK | Information | Returns TRUE if the reference to a cell is blank. | ISBLANK(Value) |
-| ISERROR | Information | The ISERROR tests if the cells contain general error values. | ISERROR(Value) |
+| ISERR | Information | Returns TRUE if the value is error value except #N/A!. | ISERR(Value) |
+| ISERROR | Information | Returns TRUE if the value is general error value. | ISERROR(Value) |
 | ISEVEN | Information | Returns TRUE if the value is an even integer, or FALSE if the value is odd. | ISEVEN(Value) |
 | ISLOGICAL | Information | Tests for a logical value (TRUE or FALSE). | ISLOGICAL(Value) |
 | ISNONTEXT | Information | Tests if the cell contents are text or numbers, and returns FALSE if the contents are text. | ISNONTEXT(Value) |
diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index d7e7192635..528ad20544 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'CELÁ.ČÁST',
     IPMT: 'PLATBA.ÚROK',
     ISBLANK: 'JE.PRÁZDNÉ',
+    ISERR: 'JE.CHYBA',
     ISERROR: 'JE.CHYBHODN',
     ISEVEN: 'ISEVEN',
     ISLOGICAL: 'JE.LOGHODN',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 81e54b65fa..e27ae3481b 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'HELTAL',
     IPMT: 'R.YDELSE',
     ISBLANK: 'ER.TOM',
+    ISERR: 'ER.FJL',
     ISERROR: 'ER.FEJL',
     ISEVEN: 'ER.LIGE',
     ISLOGICAL: 'ER.LOGISK',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 119d75150a..004eee80f1 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'GANZZAHL',
     IPMT: 'ZINSZ',
     ISBLANK: 'ISTLEER',
+    ISERR: 'ISTFEHL',
     ISERROR: 'ISTFEHLER',
     ISEVEN: 'ISTGERADE',
     ISLOGICAL: 'ISTLOG',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 679b95dd4d..c3612e37f0 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'INT',
     IPMT: 'IPMT',
     ISBLANK: 'ISBLANK',
+    ISERR: 'ISERR',
     ISERROR: 'ISERROR',
     ISEVEN: 'ISEVEN',
     ISLOGICAL: 'ISLOGICAL',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index e553ee2ad1..dcd0933350 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -78,6 +78,7 @@ export const dictionary: RawTranslationPackage = {
     INT: 'ENTERO',
     IPMT: 'PAGOINT',
     ISBLANK: 'ESBLANCO',
+    ISERR: 'ESERR',
     ISERROR: 'ESERROR',
     ISEVEN: 'ES.PAR',
     ISLOGICAL: 'ESLOGICO',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 2d1afb7f55..9ffdc12d6d 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'KOKONAISLUKU',
     IPMT: 'IPMT',
     ISBLANK: 'ONTYHJÄ',
+    ISERR: 'ONVIRH',
     ISERROR: 'ONVIRHE',
     ISEVEN: 'ONPARILLINEN',
     ISLOGICAL: 'ONTOTUUS',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 7cac6074e3..a51f89ff49 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'ENT',
     IPMT: 'INTPER',
     ISBLANK: 'ESTVIDE',
+    ISERR: 'ESTERR',
     ISERROR: 'ESTERREUR',
     ISEVEN: 'EST.PAIR',
     ISLOGICAL: 'ESTLOGIQUE',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 2e5b30ec7e..116d791e25 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'INT',
     IPMT: 'RRÉSZLET',
     ISBLANK: 'ÜRES',
+    ISERR: 'HIBA.E',
     ISERROR: 'HIBÁS',
     ISEVEN: 'PÁROSE',
     ISLOGICAL: 'LOGIKAI',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index da3dca2863..4a29d165b0 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'INT',
     IPMT: 'INTERESSI',
     ISBLANK: 'VAL.VUOTO',
+    ISERR: 'VAL.ERR',
     ISERROR: 'VAL.ERRORE',
     ISEVEN: 'VAL.PARI',
     ISLOGICAL: 'VAL.LOGICO',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 265bc3f1d6..5ccc7dd291 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'HELTALL',
     IPMT: 'RAVDRAG',
     ISBLANK: 'ERTOM',
+    ISERR: 'ERF',
     ISERROR: 'ERFEIL',
     ISEVEN: 'ERPARTALL',
     ISLOGICAL: 'ERLOGISK',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index cd9d5f6652..a3739f2d80 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'INTEGER',
     IPMT: 'IBET',
     ISBLANK: 'ISLEEG',
+    ISERR: 'ISFOUT2',
     ISERROR: 'ISFOUT',
     ISEVEN: 'IS.EVEN',
     ISLOGICAL: 'ISLOGISCH',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index 107168e1b0..df5c5af512 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'ZAOKR.DO.CAŁK',
     IPMT: 'IPMT',
     ISBLANK: 'CZY.PUSTA',
+    ISERR: 'CZY.BŁ',
     ISERROR: 'CZY.BŁĄD',
     ISEVEN: 'CZY.PARZYSTE',
     ISLOGICAL: 'CZY.LOGICZNA',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index cfa0ca781f..b961e9ac4d 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'INT',
     IPMT: 'IPGTO',
     ISBLANK: 'ÉCÉL.VAZIA',
+    ISERR: 'ÉERRO',
     ISERROR: 'ÉERROS',
     ISEVEN: 'ÉPAR',
     ISLOGICAL: 'ÉLÓGICO',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 41a3b317ec..2938048919 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'ЦЕЛОЕ',
     IPMT: 'ПРПЛТ',
     ISBLANK: 'ЕПУСТО',
+    ISERR: 'ЕОШ',
     ISERROR: 'ЕОШИБКА',
     ISEVEN: 'ЕЧЁТН',
     ISLOGICAL: 'ЕЛОГИЧ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index ea1b4f1e17..04007f77ba 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'HELTAL',
     IPMT: 'RBETALNING',
     ISBLANK: 'ÄRTOM',
+    ISERR: 'ÄRF',
     ISERROR: 'ÄRFEL',
     ISEVEN: 'ÄRJÄMN',
     ISLOGICAL: 'ÄRLOGISK',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index edf855d702..a85505437d 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -78,6 +78,7 @@ const dictionary: RawTranslationPackage = {
     INT: 'TAMSAYI',
     IPMT: 'FAİZTUTARI',
     ISBLANK: 'EBOŞSA',
+    ISERR: 'EHATA',
     ISERROR: 'EHATALIYSA',
     ISEVEN: 'ÇİFTMİ',
     ISLOGICAL: 'EMANTIKSALSA',
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index ff5f4a1049..de5a6e9972 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -14,41 +14,61 @@ import {FunctionPlugin} from './FunctionPlugin'
  */
 export class InformationPlugin extends FunctionPlugin {
   public static implementedFunctions = {
+    'ISERR': {
+      method: 'iserr',
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
+    },
     'ISERROR': {
       method: 'iserror',
-      parameters: { list: [
-        { argumentType: 'scalar'}
-      ]}
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
     },
     'ISBLANK': {
       method: 'isblank',
-      parameters: { list: [
-        { argumentType: 'scalar'}
-      ]}
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
     },
     'ISNUMBER': {
       method: 'isnumber',
-      parameters: { list: [
-        { argumentType: 'scalar'}
-      ]}
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
     },
     'ISLOGICAL': {
       method: 'islogical',
-      parameters: { list: [
-        { argumentType: 'scalar'}
-      ]}
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
     },
     'ISTEXT': {
       method: 'istext',
-      parameters: { list: [
-        { argumentType: 'scalar'}
-      ]}
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
     },
     'ISNONTEXT': {
       method: 'isnontext',
-      parameters: { list: [
-        { argumentType: 'scalar'}
-      ]}
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
     },
     'COLUMNS': {
       method: 'columns',
@@ -62,7 +82,21 @@ export class InformationPlugin extends FunctionPlugin {
     },
     'INDEX': {
       method: 'index',
-    },
+    }
+  }
+
+  /**
+   * Corresponds to ISERR(value)
+   *
+   * Returns true if provided value is an error except #N/A!
+   *
+   * @param ast
+   * @param formulaAddress
+   */
+  public iserr(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISERR'), (arg: InternalScalarValue) =>
+      (arg instanceof CellError && arg.type !== ErrorType.NA)
+    )
   }
 
   /**
@@ -148,6 +182,7 @@ export class InformationPlugin extends FunctionPlugin {
       (typeof arg !== 'string')
     )
   }
+
   /**
    * Corresponds to COLUMNS(range)
    *
diff --git a/test/interpreter/function-iserr.spec.ts b/test/interpreter/function-iserr.spec.ts
new file mode 100644
index 0000000000..b678e8eec4
--- /dev/null
+++ b/test/interpreter/function-iserr.spec.ts
@@ -0,0 +1,52 @@
+import {HyperFormula} from '../../src'
+import {ErrorType} from '../../src/Cell'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function ISERR', () => {
+  it('should return true for common errors', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISERR(1/0)', '=ISERR(FOO())'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(true)
+    expect(engine.getCellValue(adr('B1'))).toEqual(true)
+  })
+
+  it('should return false for #N/A!', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISERR(TRUE(1))'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(false)
+  })
+
+  it('should return false for valid formulas', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISERR(1)', '=ISERR(TRUE())',  '=ISERR("foo")', '=ISERR(ISERR(1/0))', '=ISERR(A1)'],
+    ])
+    expect(engine.getCellValue(adr('A1'))).toEqual(false)
+    expect(engine.getCellValue(adr('B1'))).toEqual(false)
+    expect(engine.getCellValue(adr('C1'))).toEqual(false)
+    expect(engine.getCellValue(adr('D1'))).toEqual(false)
+    expect(engine.getCellValue(adr('E1'))).toEqual(false)
+  })
+
+  it('takes exactly one argument', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISERR(1, 2)', '=ISERR()'],
+    ])
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('B1'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  // Inconsistency with Product 1
+  it('range value results in VALUE error', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=4/1'],
+      ['=4/0', '=ISERR(A1:A3)'],
+      ['=4/2'],
+    ])
+
+    expect(engine.getCellValue(adr('B2'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+})

From 5e8a3c9a774f90db5693180109e4f503b2921fb5 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 24 Jul 2020 12:56:25 +0200
Subject: [PATCH 72/97] Refactor isEven/isOdd functions

---
 src/interpreter/plugin/IsEvenPlugin.ts | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/interpreter/plugin/IsEvenPlugin.ts b/src/interpreter/plugin/IsEvenPlugin.ts
index f8154d7b4e..554764753e 100644
--- a/src/interpreter/plugin/IsEvenPlugin.ts
+++ b/src/interpreter/plugin/IsEvenPlugin.ts
@@ -11,9 +11,11 @@ export class IsEvenPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISEVEN': {
       method: 'iseven',
-      parameters: { list: [
-        { argumentType: 'number'}
-      ]}
+      parameters: {
+        list: [
+          {argumentType: 'number'}
+        ]
+      }
     },
   }
 

From 88109d63bf9d9ffdfc7248093a0d74d1d27de2a8 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 24 Jul 2020 13:12:52 +0200
Subject: [PATCH 73/97] Function ISNA

---
 docs/guide/built-in-functions.md            |  1 +
 src/i18n/languages/csCZ.ts                  |  1 +
 src/i18n/languages/daDK.ts                  |  1 +
 src/i18n/languages/deDE.ts                  |  1 +
 src/i18n/languages/enGB.ts                  |  1 +
 src/i18n/languages/esES.ts                  |  1 +
 src/i18n/languages/fiFI.ts                  |  1 +
 src/i18n/languages/frFR.ts                  |  1 +
 src/i18n/languages/huHU.ts                  |  1 +
 src/i18n/languages/itIT.ts                  |  1 +
 src/i18n/languages/nbNO.ts                  |  1 +
 src/i18n/languages/nlNL.ts                  |  1 +
 src/i18n/languages/plPL.ts                  |  1 +
 src/i18n/languages/ptPT.ts                  |  1 +
 src/i18n/languages/ruRU.ts                  |  1 +
 src/i18n/languages/svSE.ts                  |  1 +
 src/i18n/languages/trTR.ts                  |  1 +
 src/interpreter/plugin/InformationPlugin.ts | 20 ++++++++++
 test/interpreter/function-isna.spec.ts      | 41 +++++++++++++++++++++
 19 files changed, 78 insertions(+)
 create mode 100644 test/interpreter/function-isna.spec.ts

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index 54bebc414f..99a2384c65 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -86,6 +86,7 @@ lets you design your own [custom functions](custom-functions).
 | ISERROR | Information | Returns TRUE if the value is general error value. | ISERROR(Value) |
 | ISEVEN | Information | Returns TRUE if the value is an even integer, or FALSE if the value is odd. | ISEVEN(Value) |
 | ISLOGICAL | Information | Tests for a logical value (TRUE or FALSE). | ISLOGICAL(Value) |
+| ISNA | Information | Returns TRUE if the value is #N/A! error. | ISNA(Value) |
 | ISNONTEXT | Information | Tests if the cell contents are text or numbers, and returns FALSE if the contents are text. | ISNONTEXT(Value) |
 | ISNUMBER | Information | Returns TRUE if the value refers to a number. | ISNUMBER(Value) |
 | ISODD | Information | Returns TRUE if the value is odd, or FALSE if the number is even. | ISODD(Value) |
diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 528ad20544..e533deea9d 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'JE.CHYBHODN',
     ISEVEN: 'ISEVEN',
     ISLOGICAL: 'JE.LOGHODN',
+    ISNA: 'JE.NEDEF',
     ISNONTEXT: 'JE.NETEXT',
     ISNUMBER: 'JE.ČISLO',
     ISODD: 'ISODD',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index e27ae3481b..35a449c450 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ER.FEJL',
     ISEVEN: 'ER.LIGE',
     ISLOGICAL: 'ER.LOGISK',
+    ISNA: 'ER.IKKE.TILGÆNGELIG',
     ISNONTEXT: 'ER.IKKE.TEKST',
     ISNUMBER: 'ER.TAL',
     ISODD: 'ER.ULIGE',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 004eee80f1..fb0f483737 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ISTFEHLER',
     ISEVEN: 'ISTGERADE',
     ISLOGICAL: 'ISTLOG',
+    ISNA: 'ISTNV',
     ISNONTEXT: 'ISTKTEXT',
     ISNUMBER: 'ISTZAHL',
     ISODD: 'ISTUNGERADE',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index c3612e37f0..ff780f3da2 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ISERROR',
     ISEVEN: 'ISEVEN',
     ISLOGICAL: 'ISLOGICAL',
+    ISNA: 'ISNA',
     ISNONTEXT: 'ISNONTEXT',
     ISNUMBER: 'ISNUMBER',
     ISODD: 'ISODD',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index dcd0933350..cc2541b014 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -82,6 +82,7 @@ export const dictionary: RawTranslationPackage = {
     ISERROR: 'ESERROR',
     ISEVEN: 'ES.PAR',
     ISLOGICAL: 'ESLOGICO',
+    ISNA: 'ESNOD',
     ISNONTEXT: 'ESNOTEXTO',
     ISNUMBER: 'ESNUMERO',
     ISODD: 'ES.IMPAR',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 9ffdc12d6d..b6c4912711 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ONVIRHE',
     ISEVEN: 'ONPARILLINEN',
     ISLOGICAL: 'ONTOTUUS',
+    ISNA: 'ONPUUTTUU',
     ISNONTEXT: 'ONEI_TEKSTI',
     ISNUMBER: 'ONLUKU',
     ISODD: 'ONPARITON',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index a51f89ff49..50e59da077 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ESTERREUR',
     ISEVEN: 'EST.PAIR',
     ISLOGICAL: 'ESTLOGIQUE',
+    ISNA: 'ESTNA',
     ISNONTEXT: 'ESTNONTEXTE',
     ISNUMBER: 'ESTNUM',
     ISODD: 'EST.IMPAIR',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 116d791e25..cef8f440eb 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'HIBÁS',
     ISEVEN: 'PÁROSE',
     ISLOGICAL: 'LOGIKAI',
+    ISNA: 'NINCS',
     ISNONTEXT: 'NEM.SZÖVEG',
     ISNUMBER: 'SZÁM',
     ISODD: 'PÁRATLANE',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 4a29d165b0..82ccc34bc8 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'VAL.ERRORE',
     ISEVEN: 'VAL.PARI',
     ISLOGICAL: 'VAL.LOGICO',
+    ISNA: 'VAL.NON.DISP',
     ISNONTEXT: 'VAL.NON.TESTO',
     ISNUMBER: 'VAL.NUMERO',
     ISODD: 'VAL.DISPARI',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 5ccc7dd291..2aceb95c17 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ERFEIL',
     ISEVEN: 'ERPARTALL',
     ISLOGICAL: 'ERLOGISK',
+    ISNA: 'ERIT',
     ISNONTEXT: 'ERIKKETEKST',
     ISNUMBER: 'ERTALL',
     ISODD: 'ERODDE',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index a3739f2d80..a3ad208f2d 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ISFOUT',
     ISEVEN: 'IS.EVEN',
     ISLOGICAL: 'ISLOGISCH',
+    ISNA: 'ISNB',
     ISNONTEXT: 'ISGEENTEKST',
     ISNUMBER: 'ISGETAL',
     ISODD: 'IS.ONEVEN',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index df5c5af512..d9953d2504 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'CZY.BŁĄD',
     ISEVEN: 'CZY.PARZYSTE',
     ISLOGICAL: 'CZY.LOGICZNA',
+    ISNA: 'CZY.BRAK',
     ISNONTEXT: 'CZY.NIE.TEKST',
     ISNUMBER: 'CZY.LICZBA',
     ISODD: 'CZY.NIEPARZYSTE',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index b961e9ac4d..9c609c597f 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ÉERROS',
     ISEVEN: 'ÉPAR',
     ISLOGICAL: 'ÉLÓGICO',
+    ISNA: 'É.NÃO.DISP',
     ISNONTEXT: 'É.NÃO.TEXTO',
     ISNUMBER: 'ÉNÚM',
     ISODD: 'ÉIMPAR',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 2938048919..936b401e56 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ЕОШИБКА',
     ISEVEN: 'ЕЧЁТН',
     ISLOGICAL: 'ЕЛОГИЧ',
+    ISNA: 'ЕНД',
     ISNONTEXT: 'ЕНЕТЕКСТ',
     ISNUMBER: 'ЕЧИСЛО',
     ISODD: 'ЕНЕЧЁТ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 04007f77ba..40ce4b1403 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'ÄRFEL',
     ISEVEN: 'ÄRJÄMN',
     ISLOGICAL: 'ÄRLOGISK',
+    ISNA: 'ÄRSAKNAD',
     ISNONTEXT: 'ÄREJTEXT',
     ISNUMBER: 'ÄRTAL',
     ISODD: 'ÄRUDDA',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index a85505437d..e54cffd56c 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERROR: 'EHATALIYSA',
     ISEVEN: 'ÇİFTMİ',
     ISLOGICAL: 'EMANTIKSALSA',
+    ISNA: 'EYOKSA',
     ISNONTEXT: 'EMETİNDEĞİLSE',
     ISNUMBER: 'ESAYIYSA',
     ISODD: 'TEKMİ',
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index de5a6e9972..49bf14bfb5 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -38,6 +38,12 @@ export class InformationPlugin extends FunctionPlugin {
         ]
       }
     },
+    'ISNA': {
+      method: 'isna',
+      parameters: [
+        { argumentType: 'scalar'}
+      ]
+    },
     'ISNUMBER': {
       method: 'isnumber',
       parameters: {
@@ -127,6 +133,20 @@ export class InformationPlugin extends FunctionPlugin {
     )
   }
 
+  /**
+   * Corresponds to ISNA(value)
+   *
+   * Returns true if provided value is #N/A! error
+   *
+   * @param ast
+   * @param formulaAddress
+   */
+  public isna(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNA.parameters, (arg: InternalScalarValue) =>
+      (arg instanceof CellError && arg.type == ErrorType.NA)
+    )
+  }
+
   /**
    * Corresponds to ISNUMBER(value)
    *
diff --git a/test/interpreter/function-isna.spec.ts b/test/interpreter/function-isna.spec.ts
new file mode 100644
index 0000000000..954892e916
--- /dev/null
+++ b/test/interpreter/function-isna.spec.ts
@@ -0,0 +1,41 @@
+import {HyperFormula} from '../../src'
+import {ErrorType} from '../../src/Cell'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function ISNA', () => {
+  it('should return true for #NA! error', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=TRUE(1)', '=ISNA(A1)', '=ISNA(TRUE(1))'],
+    ])
+
+    expect(engine.getCellValue(adr('B1'))).toEqual(true)
+    expect(engine.getCellValue(adr('C1'))).toEqual(true)
+  })
+
+  it('should return false for other values', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISNA(1)', '=ISNA(TRUE())',  '=ISNA("foo")', '=ISNA(A1)'],
+    ])
+    expect(engine.getCellValue(adr('A1'))).toEqual(false)
+    expect(engine.getCellValue(adr('B1'))).toEqual(false)
+    expect(engine.getCellValue(adr('C1'))).toEqual(false)
+    expect(engine.getCellValue(adr('D1'))).toEqual(false)
+  })
+
+  it('takes exactly one argument', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISNA(1, 2)', '=ISNA()'],
+    ])
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('B1'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  // Inconsistency with Product 1
+  it('range value results in VALUE error', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=TRUE(1)'],
+      ['=TRUE(1)', '=ISNA(A1:A2)'],
+    ])
+    expect(engine.getCellValue(adr('B2'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+})

From 7c33f07f148f88d635b7fdd6acebe2a043b5fa46 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 24 Jul 2020 13:42:40 +0200
Subject: [PATCH 74/97] Function ISREF

---
 docs/guide/built-in-functions.md            |  1 +
 src/i18n/languages/csCZ.ts                  |  1 +
 src/i18n/languages/daDK.ts                  |  1 +
 src/i18n/languages/deDE.ts                  |  1 +
 src/i18n/languages/enGB.ts                  |  1 +
 src/i18n/languages/esES.ts                  |  1 +
 src/i18n/languages/fiFI.ts                  |  1 +
 src/i18n/languages/frFR.ts                  |  1 +
 src/i18n/languages/huHU.ts                  |  1 +
 src/i18n/languages/itIT.ts                  |  1 +
 src/i18n/languages/nbNO.ts                  |  1 +
 src/i18n/languages/nlNL.ts                  |  1 +
 src/i18n/languages/plPL.ts                  |  1 +
 src/i18n/languages/ptPT.ts                  |  1 +
 src/i18n/languages/ruRU.ts                  |  1 +
 src/i18n/languages/svSE.ts                  |  1 +
 src/i18n/languages/trTR.ts                  |  1 +
 src/interpreter/plugin/InformationPlugin.ts | 21 ++++++++
 test/interpreter/function-isref.spec.ts     | 59 +++++++++++++++++++++
 19 files changed, 97 insertions(+)
 create mode 100644 test/interpreter/function-isref.spec.ts

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index 99a2384c65..1c6886a857 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -90,6 +90,7 @@ lets you design your own [custom functions](custom-functions).
 | ISNONTEXT | Information | Tests if the cell contents are text or numbers, and returns FALSE if the contents are text. | ISNONTEXT(Value) |
 | ISNUMBER | Information | Returns TRUE if the value refers to a number. | ISNUMBER(Value) |
 | ISODD | Information | Returns TRUE if the value is odd, or FALSE if the number is even. | ISODD(Value) |
+| ISREF | Information | Returns TRUE if provided value is #REF! error.| ISREF(Value) |
 | ISTEXT | Information | Returns TRUE if the cell contents refer to text.| ISTEXT(Value) |
 | FV | Financial | Returns the future value of an investment. | FV(Rate; Nper; Pmt[; Pv;[ Type]]) |
 | IPMT | Financial | Calculates the interest portion of a given loan payment in a given payment period. | IPMT(Rate; Per; Nper; Pv[; Fv[; Type]]) |
diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index e533deea9d..42d0ee10f0 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'JE.NETEXT',
     ISNUMBER: 'JE.ČISLO',
     ISODD: 'ISODD',
+    ISREF: 'JE.ODKAZ',
     ISTEXT: 'JE.TEXT',
     LEFT: 'ZLEVA',
     LEN: 'DÉLKA',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 35a449c450..d7a6cdf2db 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ER.IKKE.TEKST',
     ISNUMBER: 'ER.TAL',
     ISODD: 'ER.ULIGE',
+    ISREF: 'ER.REFERENCE',
     ISTEXT: 'ER.TEKST',
     LEFT: 'VENSTRE',
     LEN: 'LÆNGDE',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index fb0f483737..c27f63e90a 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ISTKTEXT',
     ISNUMBER: 'ISTZAHL',
     ISODD: 'ISTUNGERADE',
+    ISREF: 'ISTBEZUG',
     ISTEXT: 'ISTTEXT',
     LEFT: 'LINKS',
     LEN: 'LÄNGE',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index ff780f3da2..d4253cb72d 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ISNONTEXT',
     ISNUMBER: 'ISNUMBER',
     ISODD: 'ISODD',
+    ISREF: 'ISREF',
     ISTEXT: 'ISTEXT',
     LEFT: 'LEFT',
     LEN: 'LEN',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index cc2541b014..75525d9797 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -86,6 +86,7 @@ export const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ESNOTEXTO',
     ISNUMBER: 'ESNUMERO',
     ISODD: 'ES.IMPAR',
+    ISREF: 'ESREF',
     ISTEXT: 'ESTEXTO',
     LEFT: 'IZQUIERDA',
     LEN: 'LARGO',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index b6c4912711..27fbe3092d 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ONEI_TEKSTI',
     ISNUMBER: 'ONLUKU',
     ISODD: 'ONPARITON',
+    ISREF: 'ONVIITT',
     ISTEXT: 'ONTEKSTI',
     LEFT: 'VASEN',
     LEN: 'PITUUS',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 50e59da077..16f4547a2f 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ESTNONTEXTE',
     ISNUMBER: 'ESTNUM',
     ISODD: 'EST.IMPAIR',
+    ISREF: 'ESTREF',
     ISTEXT: 'ESTTEXTE',
     LEFT: 'GAUCHE',
     LEN: 'NBCAR',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index cef8f440eb..097cf5b005 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'NEM.SZÖVEG',
     ISNUMBER: 'SZÁM',
     ISODD: 'PÁRATLANE',
+    ISREF: 'HIVATKOZÁS',
     ISTEXT: 'SZÖVEG.E',
     LEFT: 'BAL',
     LEN: 'HOSSZ',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 82ccc34bc8..b8f50b2f36 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'VAL.NON.TESTO',
     ISNUMBER: 'VAL.NUMERO',
     ISODD: 'VAL.DISPARI',
+    ISREF: 'VAL.RIF',
     ISTEXT: 'VAL.TESTO',
     LEFT: 'SINISTRA',
     LEN: 'LUNGHEZZA',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 2aceb95c17..c4442a09f2 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ERIKKETEKST',
     ISNUMBER: 'ERTALL',
     ISODD: 'ERODDE',
+    ISREF: 'ERREF',
     ISTEXT: 'ERTEKST',
     LEFT: 'VENSTRE',
     LEN: 'LENGDE',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index a3ad208f2d..d00dbb76b3 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ISGEENTEKST',
     ISNUMBER: 'ISGETAL',
     ISODD: 'IS.ONEVEN',
+    ISREF: 'ISVERWIJZING',
     ISTEXT: 'ISTEKST',
     LEFT: 'LINKS',
     LEN: 'PITUUS',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index d9953d2504..8af319aa04 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'CZY.NIE.TEKST',
     ISNUMBER: 'CZY.LICZBA',
     ISODD: 'CZY.NIEPARZYSTE',
+    ISREF: 'CZY.ADR',
     ISTEXT: 'CZY.TEKST',
     LEFT: 'LEWY',
     LEN: 'DŁ',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 9c609c597f..1c14a7be21 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'É.NÃO.TEXTO',
     ISNUMBER: 'ÉNÚM',
     ISODD: 'ÉIMPAR',
+    ISREF: 'ÉREF',
     ISTEXT: 'ÉTEXTO',
     LEFT: 'ESQUERDA',
     LEN: 'NÚM.CARACT',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 936b401e56..709c244fc4 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ЕНЕТЕКСТ',
     ISNUMBER: 'ЕЧИСЛО',
     ISODD: 'ЕНЕЧЁТ',
+    ISREF: 'ЕССЫЛКА',
     ISTEXT: 'ЕТЕКСТ',
     LEFT: 'ЛЕВСИМВ',
     LEN: 'ДЛСТР',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 40ce4b1403..665a3601a2 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'ÄREJTEXT',
     ISNUMBER: 'ÄRTAL',
     ISODD: 'ÄRUDDA',
+    ISREF: 'ÄRREF',
     ISTEXT: 'ÄRTEXT',
     LEFT: 'VÄNSTER',
     LEN: 'LÄNGD',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index e54cffd56c..06154a96d7 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -86,6 +86,7 @@ const dictionary: RawTranslationPackage = {
     ISNONTEXT: 'EMETİNDEĞİLSE',
     ISNUMBER: 'ESAYIYSA',
     ISODD: 'TEKMİ',
+    ISREF: 'EREFSE',
     ISTEXT: 'EMETİNSE',
     LEFT: 'SOL',
     LEN: 'UZUNLUK',
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 49bf14bfb5..f6b5511a09 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -60,6 +60,12 @@ export class InformationPlugin extends FunctionPlugin {
         ]
       }
     },
+    'ISREF': {
+      method: 'isref',
+      parameters: [
+        { argumentType: 'scalar'}
+      ]
+    },
     'ISTEXT': {
       method: 'istext',
       parameters: {
@@ -175,6 +181,21 @@ export class InformationPlugin extends FunctionPlugin {
     )
   }
 
+  /**
+   * Corresponds to ISREF(value)
+   *
+   * Returns true if provided value is #REF! error
+   *
+   * @param ast
+   * @param formulaAddress
+   */
+  public isref(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISREF.parameters, (arg: InternalScalarValue) =>
+      (arg instanceof CellError && (arg.type == ErrorType.REF || arg.type == ErrorType.CYCLE))
+    )
+  }
+
+
   /**
    * Corresponds to ISTEXT(value)
    *
diff --git a/test/interpreter/function-isref.spec.ts b/test/interpreter/function-isref.spec.ts
new file mode 100644
index 0000000000..7005c8b0e8
--- /dev/null
+++ b/test/interpreter/function-isref.spec.ts
@@ -0,0 +1,59 @@
+import {HyperFormula} from '../../src'
+import {ErrorType} from '../../src/Cell'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function ISREF', () => {
+  it('should return true for #REF!', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=#REF!', '=ISREF(A1)'],
+    ])
+
+    expect(engine.getCellValue(adr('B1'))).toEqual(true)
+  })
+
+  it('should return true for #CYCLE!', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=A1', '=ISREF(A1)'],
+    ])
+
+    expect(engine.getCellValue(adr('B1'))).toEqual(true)
+  })
+
+  it('should return false for other values', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISREF(1)', '=ISREF(TRUE())',  '=ISREF("foo")', '=ISREF(A1)'],
+    ])
+    expect(engine.getCellValue(adr('A1'))).toEqual(false)
+    expect(engine.getCellValue(adr('B1'))).toEqual(false)
+    expect(engine.getCellValue(adr('C1'))).toEqual(false)
+    expect(engine.getCellValue(adr('D1'))).toEqual(false)
+  })
+
+  it('takes exactly one argument', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISREF(1, 2)', '=ISREF()'],
+    ])
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('B1'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  // Inconsistency with Product 1
+  it('range value results in VALUE error', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=A1'],
+      ['=A2', '=ISREF(A1:A3)'],
+    ])
+
+    expect(engine.getCellValue(adr('B2'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  // Inconsistency with Product 1
+  it('returns #CYCLE! for itself', () => {
+    /* TODO can we handle such case correctly? */
+    const engine = HyperFormula.buildFromArray([
+      ['=ISREF(A1)'],
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.CYCLE))
+  })
+})

From 56fecd97193a773670b70fff4bbfe5fe67b6432a Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 24 Jul 2020 14:02:46 +0200
Subject: [PATCH 75/97] Function NA

---
 docs/guide/built-in-functions.md            |  1 +
 src/i18n/languages/csCZ.ts                  |  1 +
 src/i18n/languages/daDK.ts                  |  1 +
 src/i18n/languages/deDE.ts                  |  1 +
 src/i18n/languages/enGB.ts                  |  1 +
 src/i18n/languages/esES.ts                  |  1 +
 src/i18n/languages/fiFI.ts                  |  1 +
 src/i18n/languages/frFR.ts                  |  1 +
 src/i18n/languages/huHU.ts                  |  1 +
 src/i18n/languages/itIT.ts                  |  1 +
 src/i18n/languages/nbNO.ts                  |  1 +
 src/i18n/languages/nlNL.ts                  |  1 +
 src/i18n/languages/plPL.ts                  |  1 +
 src/i18n/languages/ptPT.ts                  |  1 +
 src/i18n/languages/ruRU.ts                  |  1 +
 src/i18n/languages/svSE.ts                  |  1 +
 src/i18n/languages/trTR.ts                  |  1 +
 src/interpreter/plugin/InformationPlugin.ts | 15 +++++++++++++++
 test/interpreter/functions-na.spec.ts       | 13 +++++++++++++
 19 files changed, 45 insertions(+)
 create mode 100644 test/interpreter/functions-na.spec.ts

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index 1c6886a857..55437c392f 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -92,6 +92,7 @@ lets you design your own [custom functions](custom-functions).
 | ISODD | Information | Returns TRUE if the value is odd, or FALSE if the number is even. | ISODD(Value) |
 | ISREF | Information | Returns TRUE if provided value is #REF! error.| ISREF(Value) |
 | ISTEXT | Information | Returns TRUE if the cell contents refer to text.| ISTEXT(Value) |
+| NA | Information | Returns #N/A! error value.| NA(Value) |
 | FV | Financial | Returns the future value of an investment. | FV(Rate; Nper; Pmt[; Pv;[ Type]]) |
 | IPMT | Financial | Calculates the interest portion of a given loan payment in a given payment period. | IPMT(Rate; Per; Nper; Pv[; Fv[; Type]]) |
 | PMT | Financial | Returns the periodic payment for a loan. | PMT(Rate; Nper; Pv[; Fv[; Type]]) |
diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 42d0ee10f0..338003175f 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'SOUČIN.MATIC',
     MOD: 'MOD',
     MONTH: 'MĚSÍC',
+    NA: 'NEDEF',
     NOT: 'NE',
     ODD: 'ZAOKROUHLIT.NA.LICHÉ',
     OFFSET: 'POSUN',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index d7a6cdf2db..f1419177bf 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MPRODUKT',
     MOD: 'REST',
     MONTH: 'MÅNED',
+    NA: 'IKKE.TILGÆNGELIG',
     NOT: 'IKKE',
     ODD: 'ULIGE',
     OFFSET: 'FORSKYDNING',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index c27f63e90a..2969006ef6 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MMULT',
     MOD: 'REST',
     MONTH: 'MONAT',
+    NA: 'NV',
     NOT: 'NICHT',
     ODD: 'UNGERADE',
     OFFSET: 'BEREICH.VERSCHIEBEN',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index d4253cb72d..a38d3a5be8 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MMULT',
     MOD: 'MOD',
     MONTH: 'MONTH',
+    NA: 'NA',
     NOT: 'NOT',
     ODD: 'ODD',
     OFFSET: 'OFFSET',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 75525d9797..49983e8857 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -104,6 +104,7 @@ export const dictionary: RawTranslationPackage = {
     MMULT: 'MMULT',
     MOD: 'RESIDUO',
     MONTH: 'MES',
+    NA: 'NOD',
     NOT: 'NO',
     ODD: 'REDONDEA.IMPAR',
     OFFSET: 'DESREF',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 27fbe3092d..dc990f22ba 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MKERRO',
     MOD: 'JAKOJ',
     MONTH: 'KUUKAUSI',
+    NA: 'PUUTTUU',
     NOT: 'EI',
     ODD: 'PARITON',
     OFFSET: 'SIIRTYMÄ',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 16f4547a2f..4367458fda 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'PRODUITMAT',
     MOD: 'MOD',
     MONTH: 'MOIS',
+    NA: 'NA',
     NOT: 'NON',
     ODD: 'IMPAIR',
     OFFSET: 'DECALER',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 097cf5b005..83b9f5c20f 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MSZORZAT',
     MOD: 'MARADÉK',
     MONTH: 'HÓNAP',
+    NA: 'HIÁNYZIK',
     NOT: 'NEM',
     ODD: 'PÁRATLAN',
     OFFSET: 'ELTOLÁS',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index b8f50b2f36..ff37fb6733 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MATR.PRODOTTO',
     MOD: 'RESTO',
     MONTH: 'MESE',
+    NA: 'NON.DISP',
     NOT: 'NON',
     ODD: 'DISPARI',
     OFFSET: 'SCARTO',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index c4442a09f2..8d1fffd3c5 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MMULT',
     MOD: 'REST',
     MONTH: 'MÅNED',
+    NA: 'IT',
     NOT: 'IKKE',
     ODD: 'AVRUND.TIL.ODDETALL',
     OFFSET: 'FORSKYVNING',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index d00dbb76b3..ca3d62611f 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'PRODUCTMAT',
     MOD: 'REST',
     MONTH: 'MAAND',
+    NA: 'NB',
     NOT: 'NIET',
     ODD: 'ONEVEN',
     OFFSET: 'VERSCHUIVING',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index 8af319aa04..6fc6837597 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MACIERZ.ILOCZYN',
     MOD: 'MOD',
     MONTH: 'MIESIĄC',
+    NA: 'BRAK',
     NOT: 'NIE',
     ODD: 'ZAOKR.DO.NPARZ',
     OFFSET: 'PRZESUNIĘCIE',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 1c14a7be21..0e8c14030b 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MATRIZ.MULT',
     MOD: 'MOD',
     MONTH: 'MÊS',
+    NA: 'NÃO.DISP',
     NOT: 'NÃO',
     ODD: 'ÍMPAR',
     OFFSET: 'DESLOC',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 709c244fc4..0cf52209a3 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'МУМНОЖ',
     MOD: 'ОСТАТ',
     MONTH: 'МЕСЯЦ',
+    NA: 'НД',
     NOT: 'НЕ',
     ODD: 'НЕЧЁТ',
     OFFSET: 'СМЕЩ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 665a3601a2..44e947f7f2 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'MMULT',
     MOD: 'REST',
     MONTH: 'MÅNAD',
+    NA: 'SAKNAS',
     NOT: 'ICKE',
     ODD: 'UDDA',
     OFFSET: 'FÖRSKJUTNING',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 06154a96d7..1f22798e01 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -104,6 +104,7 @@ const dictionary: RawTranslationPackage = {
     MMULT: 'DÇARP',
     MOD: 'MOD',
     MONTH: 'AY',
+    NA: 'YOKSAY',
     NOT: 'DEĞİL',
     ODD: 'TEK',
     OFFSET: 'KAYDIR',
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index f6b5511a09..b1578a984c 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -94,6 +94,9 @@ export class InformationPlugin extends FunctionPlugin {
     },
     'INDEX': {
       method: 'index',
+    },
+    'NA': {
+      method: 'na'
     }
   }
 
@@ -311,4 +314,16 @@ export class InformationPlugin extends FunctionPlugin {
     const address = range.getAddress(columnValue - 1, rowValue - 1)
     return this.dependencyGraph.getCellValue(address)
   }
+
+  /**
+   * Corresponds to NA()
+   *
+   * Returns #N/A!
+   *
+   * @param _ast
+   * @param _formulaAddress
+   */
+  public na(_ast: ProcedureAst, _formulaAddress: SimpleCellAddress): InternalCellValue {
+    return new CellError(ErrorType.NA)
+  }
 }
diff --git a/test/interpreter/functions-na.spec.ts b/test/interpreter/functions-na.spec.ts
new file mode 100644
index 0000000000..f175439108
--- /dev/null
+++ b/test/interpreter/functions-na.spec.ts
@@ -0,0 +1,13 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function NA', () => {
+    it('should work', () => {
+      const engine = HyperFormula.buildFromArray([
+        ['=NA()', '=NA(1)'],
+      ])
+
+      expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+      expect(engine.getCellValue(adr('B1'))).toEqual(detailedError(ErrorType.NA))
+    })
+})
\ No newline at end of file

From b01130a8016a39caf90afd687555230f88f3cb3f Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 24 Jul 2020 14:05:42 +0200
Subject: [PATCH 76/97] Template for noarg function

---
 src/interpreter/plugin/InformationPlugin.ts | 22 ++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index b1578a984c..7f778c233a 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -40,9 +40,11 @@ export class InformationPlugin extends FunctionPlugin {
     },
     'ISNA': {
       method: 'isna',
-      parameters: [
-        { argumentType: 'scalar'}
-      ]
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
     },
     'ISNUMBER': {
       method: 'isnumber',
@@ -62,9 +64,11 @@ export class InformationPlugin extends FunctionPlugin {
     },
     'ISREF': {
       method: 'isref',
-      parameters: [
-        { argumentType: 'scalar'}
-      ]
+      parameters: {
+        list: [
+          {argumentType: 'scalar'}
+        ]
+      }
     },
     'ISTEXT': {
       method: 'istext',
@@ -151,7 +155,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isna(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISNA.parameters, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISNA'), (arg: InternalScalarValue) =>
       (arg instanceof CellError && arg.type == ErrorType.NA)
     )
   }
@@ -193,7 +197,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isref(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISREF.parameters, (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISREF'), (arg: InternalScalarValue) =>
       (arg instanceof CellError && (arg.type == ErrorType.REF || arg.type == ErrorType.CYCLE))
     )
   }
@@ -323,7 +327,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param _ast
    * @param _formulaAddress
    */
-  public na(_ast: ProcedureAst, _formulaAddress: SimpleCellAddress): InternalCellValue {
+  public na(_ast: ProcedureAst, _formulaAddress: SimpleCellAddress): CellError {
     return new CellError(ErrorType.NA)
   }
 }

From a91bf23fee181063846e9dcf6f10ba6901c901cf Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 24 Jul 2020 15:36:53 +0200
Subject: [PATCH 77/97] Function SHEET

---
 docs/guide/built-in-functions.md            |  5 +-
 src/i18n/languages/csCZ.ts                  |  1 +
 src/i18n/languages/daDK.ts                  |  1 +
 src/i18n/languages/deDE.ts                  |  1 +
 src/i18n/languages/enGB.ts                  |  1 +
 src/i18n/languages/esES.ts                  |  1 +
 src/i18n/languages/fiFI.ts                  |  1 +
 src/i18n/languages/frFR.ts                  |  1 +
 src/i18n/languages/huHU.ts                  |  1 +
 src/i18n/languages/itIT.ts                  |  1 +
 src/i18n/languages/nbNO.ts                  |  1 +
 src/i18n/languages/nlNL.ts                  |  1 +
 src/i18n/languages/plPL.ts                  |  1 +
 src/i18n/languages/ptPT.ts                  |  1 +
 src/i18n/languages/ruRU.ts                  |  1 +
 src/i18n/languages/svSE.ts                  |  1 +
 src/i18n/languages/trTR.ts                  |  1 +
 src/interpreter/plugin/InformationPlugin.ts | 83 +++++++++++++++++----
 test/interpreter/function-sheet.spec.ts     | 81 ++++++++++++++++++++
 19 files changed, 168 insertions(+), 17 deletions(-)
 create mode 100644 test/interpreter/function-sheet.spec.ts

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index 55437c392f..fc07166ddd 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -90,8 +90,9 @@ lets you design your own [custom functions](custom-functions).
 | ISNONTEXT | Information | Tests if the cell contents are text or numbers, and returns FALSE if the contents are text. | ISNONTEXT(Value) |
 | ISNUMBER | Information | Returns TRUE if the value refers to a number. | ISNUMBER(Value) |
 | ISODD | Information | Returns TRUE if the value is odd, or FALSE if the number is even. | ISODD(Value) |
-| ISREF | Information | Returns TRUE if provided value is #REF! error.| ISREF(Value) |
-| ISTEXT | Information | Returns TRUE if the cell contents refer to text.| ISTEXT(Value) |
+| ISREF | Information | Returns TRUE if provided value is #REF! error. | ISREF(Value) |
+| ISTEXT | Information | Returns TRUE if the cell contents refer to text. | ISTEXT(Value) |
+| SHEET | Information | Returns sheet number of a given value or a formula sheet number if no argument is provided. | SHEET([Value]) |
 | NA | Information | Returns #N/A! error value.| NA(Value) |
 | FV | Financial | Returns the future value of an investment. | FV(Rate; Nper; Pmt[; Pv;[ Type]]) |
 | IPMT | Financial | Calculates the interest portion of a given loan payment in a given payment period. | IPMT(Rate; Per; Nper; Pv[; Fv[; Type]]) |
diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 338003175f..ea24e18e5a 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ROUNDUP',
     ROWS: 'ŘÁDKY',
     SEARCH: 'HLEDAT',
+    SHEET: 'SHEET',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'ODMOCNINA',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index f1419177bf..df73dbedca 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'RUND.OP',
     ROWS: 'RÆKKER',
     SEARCH: 'SØG',
+    SHEET: 'ARK',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'KVROD',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 2969006ef6..8550f68526 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'AUFRUNDEN',
     ROWS: 'ZEILEN',
     SEARCH: 'SUCHEN',
+    SHEET: 'BLATT',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'WURZEL',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index a38d3a5be8..b70343e5e8 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ROUNDUP',
     ROWS: 'ROWS',
     SEARCH: 'SEARCH',
+    SHEET: 'SHEET',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'SQRT',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 49983e8857..f56de563ba 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -123,6 +123,7 @@ export const dictionary: RawTranslationPackage = {
     ROUNDUP: 'REDONDEAR.MAS',
     ROWS: 'FILAS',
     SEARCH: 'HALLAR',
+    SHEET: 'HOJA',
     SIN: 'SENO',
     SPLIT: 'SPLIT',
     SQRT: 'RAIZ',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index dc990f22ba..526e9189df 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'PYÖRISTÄ.DES.YLÖS',
     ROWS: 'RIVIT',
     SEARCH: 'KÄY.LÄPI',
+    SHEET: 'TAULUKKO',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'NELIÖJUURI',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 4367458fda..1ea001bd47 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ARRONDI.SUP',
     ROWS: 'LIGNES',
     SEARCH: 'CHERCHE',
+    SHEET: 'FEUILLE',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'RACINE',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 83b9f5c20f..b3b43f57c5 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'KEREK.FEL',
     ROWS: 'SOROK',
     SEARCH: 'SZÖVEG.KERES',
+    SHEET: 'LAP',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'GYÖK',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index ff37fb6733..5a249bcab5 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ARROTONDA.PER.ECC',
     ROWS: 'RIGHE',
     SEARCH: 'RICERCA',
+    SHEET: 'FOGLIO',
     SIN: 'SEN',
     SPLIT: 'SPLIT',
     SQRT: 'RADQ',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 8d1fffd3c5..9991644ce7 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'AVRUND.OPP',
     ROWS: 'RADER',
     SEARCH: 'SØK',
+    SHEET: 'ARK',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'ROT',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index ca3d62611f..6d0937883c 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'AFRONDEN.NAAR.BOVEN',
     ROWS: 'RIJEN',
     SEARCH: 'VIND.SPEC',
+    SHEET: 'BLAD',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'WORTEL',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index 6fc6837597..deeb6acd25 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ZAOKR.GÓRA',
     ROWS: 'ILE.WIERSZY',
     SEARCH: 'SZUKAJ.TEKST',
+    SHEET: 'ARKUSZ',
     SIN: 'SIN',
     SPLIT: 'PODZIEL.TEKST',
     SQRT: 'PIERWIASTEK',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 0e8c14030b..382bb7a4cd 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ARREDONDAR.PARA.CIMA',
     ROWS: 'LINS',
     SEARCH: 'LOCALIZAR',
+    SHEET: 'PLANILHA',
     SIN: 'SEN',
     SPLIT: 'SPLIT',
     SQRT: 'RAIZ',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 0cf52209a3..40660839ab 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ОКРУГЛВВЕРХ',
     ROWS: 'ЧСТРОК',
     SEARCH: 'ПОИСК',
+    SHEET: 'ЛИСТ',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'КОРЕНЬ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 44e947f7f2..c8800b37f2 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'AVRUNDA.UPPÅT',
     ROWS: 'RADER',
     SEARCH: 'SÖK',
+    SHEET: 'SHEET',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
     SQRT: 'ROT',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 1f22798e01..6941a3067e 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'YUKARIYUVARLA',
     ROWS: 'SATIRSAY',
     SEARCH: 'MBUL',
+    SHEET: 'SAYFA',
     SIN: 'SİN',
     SPLIT: 'SPLIT',
     SQRT: 'KAREKÖK',
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 7f778c233a..26f4a50800 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -8,30 +8,36 @@ import {CellError, EmptyValue, ErrorType, InternalScalarValue, SimpleCellAddress
 import {AstNodeType, ProcedureAst} from '../../parser'
 import {InterpreterValue} from '../InterpreterValue'
 import {FunctionPlugin} from './FunctionPlugin'
+import {Maybe} from '../../Maybe'
 
 /**
  * Interpreter plugin containing information functions
  */
 export class InformationPlugin extends FunctionPlugin {
   public static implementedFunctions = {
-    'ISERR': {
-      method: 'iserr',
+    'COLUMNS': {
+      method: 'columns',
+      isDependentOnSheetStructureChange: true,
+      doesNotNeedArgumentsToBeComputed: true,
+    },
+    'ISBLANK': {
+      method: 'isblank',
       parameters: {
         list: [
           {argumentType: 'scalar'}
         ]
       }
     },
-    'ISERROR': {
-      method: 'iserror',
+    'ISERR': {
+      method: 'iserr',
       parameters: {
         list: [
           {argumentType: 'scalar'}
         ]
       }
     },
-    'ISBLANK': {
-      method: 'isblank',
+    'ISERROR': {
+      method: 'iserror',
       parameters: {
         list: [
           {argumentType: 'scalar'}
@@ -86,21 +92,25 @@ export class InformationPlugin extends FunctionPlugin {
         ]
       }
     },
-    'COLUMNS': {
-      method: 'columns',
-      isDependentOnSheetStructureChange: true,
-      doesNotNeedArgumentsToBeComputed: true,
+    'INDEX': {
+      method: 'index',
+    },
+    'NA': {
+      method: 'na'
     },
     'ROWS': {
       method: 'rows',
       isDependentOnSheetStructureChange: true,
       doesNotNeedArgumentsToBeComputed: true,
     },
-    'INDEX': {
-      method: 'index',
-    },
-    'NA': {
-      method: 'na'
+    'SHEET': {
+      method: 'sheet',
+      parameters: {
+        list: [
+          {argumentType: 'noerror'}
+        ]
+      },
+      doesNotNeedArgumentsToBeComputed: true
     }
   }
 
@@ -330,4 +340,47 @@ export class InformationPlugin extends FunctionPlugin {
   public na(_ast: ProcedureAst, _formulaAddress: SimpleCellAddress): CellError {
     return new CellError(ErrorType.NA)
   }
+
+  /**
+   * Corresponds to SHEET(value)
+   *
+   * Returns sheet number of a given value or a formula sheet number if no argument is provided
+   *
+   * @param ast
+   * @param formulaAddress
+   * */
+  public sheet(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    if (ast.args.length > 1) {
+      return new CellError(ErrorType.NA)
+    } else if (ast.args.length == 0) {
+      return formulaAddress.sheet + 1
+    }
+    const arg = ast.args[0]
+
+    let cellReference: Maybe<SimpleCellAddress>
+
+    if (arg.type === AstNodeType.CELL_REFERENCE) {
+      cellReference = arg.reference.toSimpleCellAddress(formulaAddress)
+    } else if (arg.type === AstNodeType.CELL_RANGE || arg.type === AstNodeType.COLUMN_RANGE || arg.type === AstNodeType.ROW_RANGE) {
+      try {
+        cellReference = AbsoluteCellRange.fromAst(arg, formulaAddress).start
+      } catch (e) {
+        return new CellError(ErrorType.REF)
+      }
+    }
+
+    if (cellReference !== undefined) {
+      return cellReference.sheet + 1
+    }
+
+    /* Not using static parameters definition as we expect only values coerced to string from now on. */
+    return this.runFunction(ast.args, formulaAddress, { list: [{ argumentType: 'string' }]}, (value: string) => {
+      const sheetNumber = this.dependencyGraph.sheetMapping.get(value)
+      if (sheetNumber !== undefined) {
+        return sheetNumber + 1
+      } else {
+        return new CellError(ErrorType.NA)
+      }
+    })
+  }
 }
diff --git a/test/interpreter/function-sheet.spec.ts b/test/interpreter/function-sheet.spec.ts
new file mode 100644
index 0000000000..7018a397f3
--- /dev/null
+++ b/test/interpreter/function-sheet.spec.ts
@@ -0,0 +1,81 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function SHEET', () => {
+  it('should return formula sheet number', () => {
+    const engine = HyperFormula.buildFromSheets({
+      'Sheet1': [['=SHEET()']],
+      'Sheet2': [['=SHEET()']],
+    })
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A1', 1))).toEqual(2)
+  })
+
+  it('should return reference sheet number for self sheet reference', () => {
+    const engine = HyperFormula.buildFromSheets({
+      'Sheet1': [['=SHEET(B1)']],
+      'Sheet2': [['=SHEET(B1)', '=1/0']],
+    })
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('A1', 1))).toEqual(2)
+  })
+
+  it('should return reference sheet number for absolute sheet reference', () => {
+    const engine = HyperFormula.buildFromSheets({
+      'Sheet1': [['=SHEET(Sheet1!B1)', '=SHEET(Sheet2!B1)']],
+      'Sheet2': [['=SHEET(Sheet1!B1)', '=SHEET(Sheet2!B2)']],
+    })
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('B1'))).toEqual(2)
+    expect(engine.getCellValue(adr('A1', 1))).toEqual(1)
+    expect(engine.getCellValue(adr('B1', 1))).toEqual(2)
+  })
+
+  it('should return range sheet number', () => {
+    const engine = HyperFormula.buildFromSheets({
+      'Sheet1': [['=SHEET(B1:B2)', '=SHEET(Sheet2!A1:B1)']],
+      'Sheet2': [['=SHEET(B1:B2)', '=SHEET(Sheet1!A1:B1)']],
+    })
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('B1'))).toEqual(2)
+    expect(engine.getCellValue(adr('A1', 1))).toEqual(2)
+    expect(engine.getCellValue(adr('B1', 1))).toEqual(1)
+  })
+
+  it('should return VALUE for non existing sheet', () => {
+    const engine = HyperFormula.buildFromSheets({
+      'Sheet1': [['=SHEET("FOO")', '=SHEET(1)']],
+    })
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('B1'))).toEqual(detailedError(ErrorType.NA))
+  })
+
+  it('should coerce', () => {
+    const engine = HyperFormula.buildFromArray([])
+    engine.addSheet('TRUE')
+    engine.addSheet('1')
+
+    engine.setCellContents(adr('A1'), [['=SHEET(1=1)']])
+    engine.setCellContents(adr('B1'), [['=SHEET(1)']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(2)
+    expect(engine.getCellValue(adr('B1'))).toEqual(3)
+  })
+
+  it('should propagate errors', () => {
+    const engine = HyperFormula.buildFromArray([['=SHEET(1/0)']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.DIV_BY_ZERO))
+  })
+
+  it('should work for itself', () => {
+    const engine = HyperFormula.buildFromArray([['=SHEET(A1)']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+  })
+})
\ No newline at end of file

From 6cb84edc34b51658e1f2d55bcbf22d8abaac1dc6 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Fri, 24 Jul 2020 16:09:28 +0200
Subject: [PATCH 78/97] Function SHEETS

---
 docs/guide/built-in-functions.md            |  1 +
 src/i18n/languages/csCZ.ts                  |  1 +
 src/i18n/languages/daDK.ts                  |  1 +
 src/i18n/languages/deDE.ts                  |  1 +
 src/i18n/languages/enGB.ts                  |  1 +
 src/i18n/languages/esES.ts                  |  1 +
 src/i18n/languages/fiFI.ts                  |  1 +
 src/i18n/languages/frFR.ts                  |  1 +
 src/i18n/languages/huHU.ts                  |  1 +
 src/i18n/languages/itIT.ts                  |  1 +
 src/i18n/languages/nbNO.ts                  |  1 +
 src/i18n/languages/nlNL.ts                  |  1 +
 src/i18n/languages/plPL.ts                  |  1 +
 src/i18n/languages/ptPT.ts                  |  1 +
 src/i18n/languages/ruRU.ts                  |  1 +
 src/i18n/languages/svSE.ts                  |  1 +
 src/i18n/languages/trTR.ts                  |  1 +
 src/interpreter/plugin/InformationPlugin.ts | 42 ++++++++++++++++++++-
 test/interpreter/function-sheets.spec.ts    | 42 +++++++++++++++++++++
 19 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 test/interpreter/function-sheets.spec.ts

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index fc07166ddd..101358c648 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -93,6 +93,7 @@ lets you design your own [custom functions](custom-functions).
 | ISREF | Information | Returns TRUE if provided value is #REF! error. | ISREF(Value) |
 | ISTEXT | Information | Returns TRUE if the cell contents refer to text. | ISTEXT(Value) |
 | SHEET | Information | Returns sheet number of a given value or a formula sheet number if no argument is provided. | SHEET([Value]) |
+| SHEETS | Information | Returns number of sheet of a given reference or number of all sheets in workbook when no argument is provided. | SHEETS([Value]) |
 | NA | Information | Returns #N/A! error value.| NA(Value) |
 | FV | Financial | Returns the future value of an investment. | FV(Rate; Nper; Pmt[; Pv;[ Type]]) |
 | IPMT | Financial | Calculates the interest portion of a given loan payment in a given payment period. | IPMT(Rate; Per; Nper; Pv[; Fv[; Type]]) |
diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index ea24e18e5a..14afe9818d 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ROUNDUP',
     ROWS: 'ŘÁDKY',
     SEARCH: 'HLEDAT',
+    SHEETS: 'SHEETS',
     SHEET: 'SHEET',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index df73dbedca..00516ebb17 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'RUND.OP',
     ROWS: 'RÆKKER',
     SEARCH: 'SØG',
+    SHEETS: 'ARK.FLERE',
     SHEET: 'ARK',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 8550f68526..b876702876 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'AUFRUNDEN',
     ROWS: 'ZEILEN',
     SEARCH: 'SUCHEN',
+    SHEETS: 'BLÄTTER',
     SHEET: 'BLATT',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index b70343e5e8..23bc9db587 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ROUNDUP',
     ROWS: 'ROWS',
     SEARCH: 'SEARCH',
+    SHEETS: 'SHEETS',
     SHEET: 'SHEET',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index f56de563ba..d533cdff7f 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -123,6 +123,7 @@ export const dictionary: RawTranslationPackage = {
     ROUNDUP: 'REDONDEAR.MAS',
     ROWS: 'FILAS',
     SEARCH: 'HALLAR',
+    SHEETS: 'HOJAS',
     SHEET: 'HOJA',
     SIN: 'SENO',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 526e9189df..9cdb6c9283 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'PYÖRISTÄ.DES.YLÖS',
     ROWS: 'RIVIT',
     SEARCH: 'KÄY.LÄPI',
+    SHEETS: 'TAULUKOT',
     SHEET: 'TAULUKKO',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 1ea001bd47..7126818b8d 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ARRONDI.SUP',
     ROWS: 'LIGNES',
     SEARCH: 'CHERCHE',
+    SHEETS: 'FEUILLES',
     SHEET: 'FEUILLE',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index b3b43f57c5..de18289d59 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'KEREK.FEL',
     ROWS: 'SOROK',
     SEARCH: 'SZÖVEG.KERES',
+    SHEETS: 'LAPOK',
     SHEET: 'LAP',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 5a249bcab5..9c6313078d 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ARROTONDA.PER.ECC',
     ROWS: 'RIGHE',
     SEARCH: 'RICERCA',
+    SHEETS: 'FOGLI',
     SHEET: 'FOGLIO',
     SIN: 'SEN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 9991644ce7..bea65ec68a 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'AVRUND.OPP',
     ROWS: 'RADER',
     SEARCH: 'SØK',
+    SHEETS: 'SHEETS',
     SHEET: 'ARK',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index 6d0937883c..05d2b7c451 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'AFRONDEN.NAAR.BOVEN',
     ROWS: 'RIJEN',
     SEARCH: 'VIND.SPEC',
+    SHEETS: 'BLADEN',
     SHEET: 'BLAD',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index deeb6acd25..fb9c40b00e 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ZAOKR.GÓRA',
     ROWS: 'ILE.WIERSZY',
     SEARCH: 'SZUKAJ.TEKST',
+    SHEETS: 'ARKUSZE',
     SHEET: 'ARKUSZ',
     SIN: 'SIN',
     SPLIT: 'PODZIEL.TEKST',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 382bb7a4cd..e4b8bd383f 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ARREDONDAR.PARA.CIMA',
     ROWS: 'LINS',
     SEARCH: 'LOCALIZAR',
+    SHEETS: 'PLANILHAS',
     SHEET: 'PLANILHA',
     SIN: 'SEN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 40660839ab..a977117c39 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'ОКРУГЛВВЕРХ',
     ROWS: 'ЧСТРОК',
     SEARCH: 'ПОИСК',
+    SHEETS: 'ЛИСТЫ',
     SHEET: 'ЛИСТ',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index c8800b37f2..62fcc8ab2d 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'AVRUNDA.UPPÅT',
     ROWS: 'RADER',
     SEARCH: 'SÖK',
+    SHEETS: 'SHEETS',
     SHEET: 'SHEET',
     SIN: 'SIN',
     SPLIT: 'SPLIT',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 6941a3067e..ca77c02c71 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -123,6 +123,7 @@ const dictionary: RawTranslationPackage = {
     ROUNDUP: 'YUKARIYUVARLA',
     ROWS: 'SATIRSAY',
     SEARCH: 'MBUL',
+    SHEETS: 'SAYFALAR',
     SHEET: 'SAYFA',
     SIN: 'SİN',
     SPLIT: 'SPLIT',
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 26f4a50800..b40594342b 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -111,6 +111,15 @@ export class InformationPlugin extends FunctionPlugin {
         ]
       },
       doesNotNeedArgumentsToBeComputed: true
+    },
+    'SHEETS': {
+      method: 'sheets',
+      parameters: {
+        list: [
+          {argumentType: 'noerror'}
+        ]
+      },
+      doesNotNeedArgumentsToBeComputed: true
     }
   }
 
@@ -374,7 +383,7 @@ export class InformationPlugin extends FunctionPlugin {
     }
 
     /* Not using static parameters definition as we expect only values coerced to string from now on. */
-    return this.runFunction(ast.args, formulaAddress, { list: [{ argumentType: 'string' }]}, (value: string) => {
+    return this.runFunction(ast.args, formulaAddress, {list: [{argumentType: 'string'}]}, (value: string) => {
       const sheetNumber = this.dependencyGraph.sheetMapping.get(value)
       if (sheetNumber !== undefined) {
         return sheetNumber + 1
@@ -383,4 +392,35 @@ export class InformationPlugin extends FunctionPlugin {
       }
     })
   }
+
+  /**
+   * Corresponds to SHEETS(value)
+   *
+   * Returns number of sheet of a given reference or number of all sheets in workbook when no argument is provided.
+   * It returns always 1 for a valid reference as 3D references are not supported.
+   *
+   * @param ast
+   * @param formulaAddress
+   * */
+  public sheets(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    if (ast.args.length > 1) {
+      return new CellError(ErrorType.NA)
+    } else if (ast.args.length == 0) {
+      return this.dependencyGraph.sheetMapping.numberOfSheets()
+    }
+
+    const arg = ast.args[0]
+    if (
+      arg.type === AstNodeType.CELL_REFERENCE ||
+      arg.type === AstNodeType.CELL_RANGE ||
+      arg.type === AstNodeType.COLUMN_RANGE ||
+      arg.type === AstNodeType.ROW_RANGE
+    ) {
+      return 1
+    }
+
+    return this.runFunction(ast.args, formulaAddress, this.parameters('SHEETS'), () => {
+      return new CellError(ErrorType.VALUE)
+    })
+  }
 }
diff --git a/test/interpreter/function-sheets.spec.ts b/test/interpreter/function-sheets.spec.ts
new file mode 100644
index 0000000000..00e1679f4b
--- /dev/null
+++ b/test/interpreter/function-sheets.spec.ts
@@ -0,0 +1,42 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function SHEETS', () => {
+  it('should return number of sheets if no argument provided', () => {
+    const engine = HyperFormula.buildFromSheets({
+      'Sheet1': [['=SHEETS()']],
+      'Sheet2': [],
+    })
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(2)
+  })
+
+  it('should return 1 for a valid reference', () => {
+    const engine = HyperFormula.buildFromArray([['=SHEETS(B1)', '=SHEETS(A1:A2)', '=SHEETS(A:B)', '=SHEETS(1:2)']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+    expect(engine.getCellValue(adr('B1'))).toEqual(1)
+    expect(engine.getCellValue(adr('C1'))).toEqual(1)
+    expect(engine.getCellValue(adr('D1'))).toEqual(1)
+  })
+
+  it('should return VALUE for non-reference parameter', () => {
+    const engine = HyperFormula.buildFromArray([['=SHEETS(1)', '=SHEETS("foo")', '=SHEETS(TRUE())']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('B1'))).toEqual(detailedError(ErrorType.VALUE))
+    expect(engine.getCellValue(adr('C1'))).toEqual(detailedError(ErrorType.VALUE))
+  })
+
+  it('should propagate errors', () => {
+    const engine = HyperFormula.buildFromArray([['=SHEETS(1/0)']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.DIV_BY_ZERO))
+  })
+
+  it('should work for itself', () => {
+    const engine = HyperFormula.buildFromArray([['=SHEETS(A1)']])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(1)
+  })
+})
\ No newline at end of file

From 71e9d2ffd2ad7f0027b7c2adaf678b77520c91d5 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Sat, 25 Jul 2020 09:05:20 +0200
Subject: [PATCH 79/97] Function ISBINARY

---
 docs/guide/built-in-functions.md            |  1 +
 src/i18n/languages/csCZ.ts                  |  1 +
 src/i18n/languages/daDK.ts                  |  1 +
 src/i18n/languages/deDE.ts                  |  1 +
 src/i18n/languages/enGB.ts                  |  1 +
 src/i18n/languages/esES.ts                  |  1 +
 src/i18n/languages/fiFI.ts                  |  1 +
 src/i18n/languages/frFR.ts                  |  1 +
 src/i18n/languages/huHU.ts                  |  1 +
 src/i18n/languages/itIT.ts                  |  1 +
 src/i18n/languages/nbNO.ts                  |  1 +
 src/i18n/languages/nlNL.ts                  |  1 +
 src/i18n/languages/plPL.ts                  |  1 +
 src/i18n/languages/ptPT.ts                  |  1 +
 src/i18n/languages/ruRU.ts                  |  1 +
 src/i18n/languages/svSE.ts                  |  1 +
 src/i18n/languages/trTR.ts                  |  1 +
 src/interpreter/plugin/InformationPlugin.ts | 20 +++++++++++++++++
 test/interpreter/function-isbinary.spec.ts  | 24 +++++++++++++++++++++
 19 files changed, 61 insertions(+)
 create mode 100644 test/interpreter/function-isbinary.spec.ts

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index 101358c648..912afd4079 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -81,6 +81,7 @@ lets you design your own [custom functions](custom-functions).
 | DELTA | Engineering | Returns TRUE (1) if both numbers are equal, otherwise returns FALSE (0). | DELTA(Number_1; Number_2) |
 | ERF | Engineering | Returns values of the Gaussian error integral. | ERF(Lower_Limit; Upper_Limit) |
 | ERFC | Engineering | Returns complementary values of the Gaussian error integral between x and infinity. | ERFC(Lower_Limit) |
+| ISBINARY | Information | Returns TRUE if provided value is a valid binary number. | ISBINARY(Value) |
 | ISBLANK | Information | Returns TRUE if the reference to a cell is blank. | ISBLANK(Value) |
 | ISERR | Information | Returns TRUE if the value is error value except #N/A!. | ISERR(Value) |
 | ISERROR | Information | Returns TRUE if the value is general error value. | ISERROR(Value) |
diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 14afe9818d..94316f8537 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEX',
     INT: 'CELÁ.ČÁST',
     IPMT: 'PLATBA.ÚROK',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'JE.PRÁZDNÉ',
     ISERR: 'JE.CHYBA',
     ISERROR: 'JE.CHYBHODN',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 00516ebb17..7ca27a951d 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEKS',
     INT: 'HELTAL',
     IPMT: 'R.YDELSE',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ER.TOM',
     ISERR: 'ER.FJL',
     ISERROR: 'ER.FEJL',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index b876702876..38d97dc319 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEX',
     INT: 'GANZZAHL',
     IPMT: 'ZINSZ',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ISTLEER',
     ISERR: 'ISTFEHL',
     ISERROR: 'ISTFEHLER',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 23bc9db587..8c10eedbe8 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEX',
     INT: 'INT',
     IPMT: 'IPMT',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ISBLANK',
     ISERR: 'ISERR',
     ISERROR: 'ISERROR',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index d533cdff7f..183b913b10 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -77,6 +77,7 @@ export const dictionary: RawTranslationPackage = {
     INDEX: 'INDICE',
     INT: 'ENTERO',
     IPMT: 'PAGOINT',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ESBLANCO',
     ISERR: 'ESERR',
     ISERROR: 'ESERROR',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index 9cdb6c9283..c2ceefc3f2 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEKSI',
     INT: 'KOKONAISLUKU',
     IPMT: 'IPMT',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ONTYHJÄ',
     ISERR: 'ONVIRH',
     ISERROR: 'ONVIRHE',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index 7126818b8d..e6fa7b17a8 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEX',
     INT: 'ENT',
     IPMT: 'INTPER',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ESTVIDE',
     ISERR: 'ESTERR',
     ISERROR: 'ESTERREUR',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index de18289d59..3e86a27c2e 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEX',
     INT: 'INT',
     IPMT: 'RRÉSZLET',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ÜRES',
     ISERR: 'HIBA.E',
     ISERROR: 'HIBÁS',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index 9c6313078d..a883ac5a17 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDICE',
     INT: 'INT',
     IPMT: 'INTERESSI',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'VAL.VUOTO',
     ISERR: 'VAL.ERR',
     ISERROR: 'VAL.ERRORE',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index bea65ec68a..20bd3e345f 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEKS',
     INT: 'HELTALL',
     IPMT: 'RAVDRAG',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ERTOM',
     ISERR: 'ERF',
     ISERROR: 'ERFEIL',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index 05d2b7c451..9ccfc8b237 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEX',
     INT: 'INTEGER',
     IPMT: 'IBET',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ISLEEG',
     ISERR: 'ISFOUT2',
     ISERROR: 'ISFOUT',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index fb9c40b00e..5016104c70 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEKS',
     INT: 'ZAOKR.DO.CAŁK',
     IPMT: 'IPMT',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'CZY.PUSTA',
     ISERR: 'CZY.BŁ',
     ISERROR: 'CZY.BŁĄD',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index e4b8bd383f..58aa5f7f7b 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'ÍNDICE',
     INT: 'INT',
     IPMT: 'IPGTO',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ÉCÉL.VAZIA',
     ISERR: 'ÉERRO',
     ISERROR: 'ÉERROS',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index a977117c39..3eb70bf07c 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'ИНДЕКС',
     INT: 'ЦЕЛОЕ',
     IPMT: 'ПРПЛТ',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ЕПУСТО',
     ISERR: 'ЕОШ',
     ISERROR: 'ЕОШИБКА',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index 62fcc8ab2d..f56b7ea9d5 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'INDEX',
     INT: 'HELTAL',
     IPMT: 'RBETALNING',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'ÄRTOM',
     ISERR: 'ÄRF',
     ISERROR: 'ÄRFEL',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index ca77c02c71..5f1172c2ad 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -77,6 +77,7 @@ const dictionary: RawTranslationPackage = {
     INDEX: 'İNDİS',
     INT: 'TAMSAYI',
     IPMT: 'FAİZTUTARI',
+    ISBINARY: 'ISBINARY',
     ISBLANK: 'EBOŞSA',
     ISERR: 'EHATA',
     ISERROR: 'EHATALIYSA',
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index b40594342b..199b924eff 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -20,6 +20,12 @@ export class InformationPlugin extends FunctionPlugin {
       isDependentOnSheetStructureChange: true,
       doesNotNeedArgumentsToBeComputed: true,
     },
+    'ISBINARY': {
+      method: 'isbinary',
+      parameters: [
+        {argumentType: 'string'}
+      ]
+    },
     'ISBLANK': {
       method: 'isblank',
       parameters: {
@@ -123,6 +129,20 @@ export class InformationPlugin extends FunctionPlugin {
     }
   }
 
+  /**
+   * Corresponds to ISBINARY(value)
+   *
+   * Returns true if provided value is a valid binary number
+   *
+   * @param ast
+   * @param formulaAddress
+   */
+  public isbinary(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISBINARY.parameters, (arg: string) =>
+      /^[01]{1,10}$/.test(arg)
+    )
+  }
+
   /**
    * Corresponds to ISERR(value)
    *
diff --git a/test/interpreter/function-isbinary.spec.ts b/test/interpreter/function-isbinary.spec.ts
new file mode 100644
index 0000000000..178fd5d2c8
--- /dev/null
+++ b/test/interpreter/function-isbinary.spec.ts
@@ -0,0 +1,24 @@
+import {HyperFormula} from '../../src'
+import {adr} from '../testUtils'
+
+describe('Function ISBINARY', () => {
+  it('should return true for binary numbers', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISBINARY("1010")', '=ISBINARY(1001)', '=ISBINARY(010)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(true)
+    expect(engine.getCellValue(adr('B1'))).toEqual(true)
+    expect(engine.getCellValue(adr('C1'))).toEqual(true)
+  })
+
+  it('should return false otherwise', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISBINARY("foo")', '=ISBINARY(123)', '=ISBINARY(TRUE())']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(false)
+    expect(engine.getCellValue(adr('B1'))).toEqual(false)
+    expect(engine.getCellValue(adr('C1'))).toEqual(false)
+  })
+})
\ No newline at end of file

From 2cbdf81adc9fe8763ee01932eb4501436d0ada05 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Sat, 25 Jul 2020 09:53:30 +0200
Subject: [PATCH 80/97] Reference argument template

---
 src/interpreter/plugin/InformationPlugin.ts | 104 ++++++++++----------
 1 file changed, 53 insertions(+), 51 deletions(-)

diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 199b924eff..2ca5060f09 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -5,9 +5,9 @@
 
 import {AbsoluteCellRange} from '../../AbsoluteCellRange'
 import {CellError, EmptyValue, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {Ast, AstNodeType, ProcedureAst} from '../../parser'
 import {InterpreterValue} from '../InterpreterValue'
-import {FunctionPlugin} from './FunctionPlugin'
+import {FunctionArgumentsDefinition, FunctionPlugin} from './FunctionPlugin'
 import {Maybe} from '../../Maybe'
 
 /**
@@ -22,9 +22,11 @@ export class InformationPlugin extends FunctionPlugin {
     },
     'ISBINARY': {
       method: 'isbinary',
-      parameters: [
-        {argumentType: 'string'}
-      ]
+      parameters: {
+        list: [
+          {argumentType: 'string'}
+        ]
+      }
     },
     'ISBLANK': {
       method: 'isblank',
@@ -138,7 +140,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isbinary(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithDefaults(ast.args, formulaAddress, InformationPlugin.implementedFunctions.ISBINARY.parameters, (arg: string) =>
+    return this.runFunction(ast.args, formulaAddress, this.parameters('ISBINARY'), (arg: string) =>
       /^[01]{1,10}$/.test(arg)
     )
   }
@@ -379,38 +381,18 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    * */
   public sheet(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length > 1) {
-      return new CellError(ErrorType.NA)
-    } else if (ast.args.length == 0) {
-      return formulaAddress.sheet + 1
-    }
-    const arg = ast.args[0]
-
-    let cellReference: Maybe<SimpleCellAddress>
-
-    if (arg.type === AstNodeType.CELL_REFERENCE) {
-      cellReference = arg.reference.toSimpleCellAddress(formulaAddress)
-    } else if (arg.type === AstNodeType.CELL_RANGE || arg.type === AstNodeType.COLUMN_RANGE || arg.type === AstNodeType.ROW_RANGE) {
-      try {
-        cellReference = AbsoluteCellRange.fromAst(arg, formulaAddress).start
-      } catch (e) {
-        return new CellError(ErrorType.REF)
-      }
-    }
-
-    if (cellReference !== undefined) {
-      return cellReference.sheet + 1
-    }
-
-    /* Not using static parameters definition as we expect only values coerced to string from now on. */
-    return this.runFunction(ast.args, formulaAddress, {list: [{argumentType: 'string'}]}, (value: string) => {
-      const sheetNumber = this.dependencyGraph.sheetMapping.get(value)
-      if (sheetNumber !== undefined) {
-        return sheetNumber + 1
-      } else {
-        return new CellError(ErrorType.NA)
+    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, { list: [{argumentType: 'string'}] },
+      () => formulaAddress.sheet + 1,
+      (reference: SimpleCellAddress) => reference.sheet + 1,
+      (value: string) => {
+        const sheetNumber = this.dependencyGraph.sheetMapping.get(value)
+        if (sheetNumber !== undefined) {
+          return sheetNumber + 1
+        } else {
+          return new CellError(ErrorType.NA)
+        }
       }
-    })
+    )
   }
 
   /**
@@ -423,24 +405,44 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    * */
   public sheets(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length > 1) {
+    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, { list: [{argumentType: 'string'}] },
+      () => this.dependencyGraph.sheetMapping.numberOfSheets(), // return number of sheets if no argument
+      () => 1, // return 1 for valid reference
+      () => new CellError(ErrorType.VALUE) // error otherwise
+    )
+  }
+
+  protected runFunctionWithReferenceArgument = (
+    args: Ast[],
+    formulaAddress: SimpleCellAddress,
+    argumentDefinitions: FunctionArgumentsDefinition,
+    noArgCallback: () => InternalScalarValue,
+    referenceCallback: (reference: SimpleCellAddress) => InternalScalarValue,
+    nonReferenceCallback: (...arg: any) => InternalScalarValue
+  ) => {
+    if (args.length === 0) {
+      return noArgCallback()
+    } else if (args.length > 1) {
       return new CellError(ErrorType.NA)
-    } else if (ast.args.length == 0) {
-      return this.dependencyGraph.sheetMapping.numberOfSheets()
+    }
+    const arg = args[0]
+
+    let cellReference: Maybe<SimpleCellAddress>
+
+    if (arg.type === AstNodeType.CELL_REFERENCE) {
+      cellReference = arg.reference.toSimpleCellAddress(formulaAddress)
+    } else if (arg.type === AstNodeType.CELL_RANGE || arg.type === AstNodeType.COLUMN_RANGE || arg.type === AstNodeType.ROW_RANGE) {
+      try {
+        cellReference = AbsoluteCellRange.fromAst(arg, formulaAddress).start
+      } catch (e) {
+        return new CellError(ErrorType.REF)
+      }
     }
 
-    const arg = ast.args[0]
-    if (
-      arg.type === AstNodeType.CELL_REFERENCE ||
-      arg.type === AstNodeType.CELL_RANGE ||
-      arg.type === AstNodeType.COLUMN_RANGE ||
-      arg.type === AstNodeType.ROW_RANGE
-    ) {
-      return 1
+    if (cellReference !== undefined) {
+      return referenceCallback(cellReference)
     }
 
-    return this.runFunction(ast.args, formulaAddress, this.parameters('SHEETS'), () => {
-      return new CellError(ErrorType.VALUE)
-    })
+    return this.runFunction(args, formulaAddress, argumentDefinitions, nonReferenceCallback)
   }
 }

From 0ad3bc5b26a9c4afdaf44210e0e59ea6f4a8e672 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Sat, 25 Jul 2020 10:43:04 +0200
Subject: [PATCH 81/97] Function ISFORMULA

---
 docs/guide/built-in-functions.md            |  1 +
 src/i18n/languages/csCZ.ts                  |  1 +
 src/i18n/languages/daDK.ts                  |  1 +
 src/i18n/languages/deDE.ts                  |  1 +
 src/i18n/languages/enGB.ts                  |  1 +
 src/i18n/languages/esES.ts                  |  1 +
 src/i18n/languages/fiFI.ts                  |  1 +
 src/i18n/languages/frFR.ts                  |  1 +
 src/i18n/languages/huHU.ts                  |  1 +
 src/i18n/languages/itIT.ts                  |  1 +
 src/i18n/languages/nbNO.ts                  |  1 +
 src/i18n/languages/nlNL.ts                  |  1 +
 src/i18n/languages/plPL.ts                  |  1 +
 src/i18n/languages/ptPT.ts                  |  1 +
 src/i18n/languages/ruRU.ts                  |  1 +
 src/i18n/languages/svSE.ts                  |  1 +
 src/i18n/languages/trTR.ts                  |  1 +
 src/interpreter/plugin/InformationPlugin.ts | 32 +++++++++++++-
 test/interpreter/function-isformula.spec.ts | 49 +++++++++++++++++++++
 19 files changed, 96 insertions(+), 2 deletions(-)
 create mode 100644 test/interpreter/function-isformula.spec.ts

diff --git a/docs/guide/built-in-functions.md b/docs/guide/built-in-functions.md
index 912afd4079..437ee8bf43 100644
--- a/docs/guide/built-in-functions.md
+++ b/docs/guide/built-in-functions.md
@@ -86,6 +86,7 @@ lets you design your own [custom functions](custom-functions).
 | ISERR | Information | Returns TRUE if the value is error value except #N/A!. | ISERR(Value) |
 | ISERROR | Information | Returns TRUE if the value is general error value. | ISERROR(Value) |
 | ISEVEN | Information | Returns TRUE if the value is an even integer, or FALSE if the value is odd. | ISEVEN(Value) |
+| ISFORMULA | Information | Checks whether referenced cell is a formula. | ISFORMULA(Value) |
 | ISLOGICAL | Information | Tests for a logical value (TRUE or FALSE). | ISLOGICAL(Value) |
 | ISNA | Information | Returns TRUE if the value is #N/A! error. | ISNA(Value) |
 | ISNONTEXT | Information | Tests if the cell contents are text or numbers, and returns FALSE if the contents are text. | ISNONTEXT(Value) |
diff --git a/src/i18n/languages/csCZ.ts b/src/i18n/languages/csCZ.ts
index 94316f8537..68f8a25812 100644
--- a/src/i18n/languages/csCZ.ts
+++ b/src/i18n/languages/csCZ.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'JE.CHYBA',
     ISERROR: 'JE.CHYBHODN',
     ISEVEN: 'ISEVEN',
+    ISFORMULA: 'ISFORMULA',
     ISLOGICAL: 'JE.LOGHODN',
     ISNA: 'JE.NEDEF',
     ISNONTEXT: 'JE.NETEXT',
diff --git a/src/i18n/languages/daDK.ts b/src/i18n/languages/daDK.ts
index 7ca27a951d..d1d824b767 100644
--- a/src/i18n/languages/daDK.ts
+++ b/src/i18n/languages/daDK.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ER.FJL',
     ISERROR: 'ER.FEJL',
     ISEVEN: 'ER.LIGE',
+    ISFORMULA: 'ER.FORMEL',
     ISLOGICAL: 'ER.LOGISK',
     ISNA: 'ER.IKKE.TILGÆNGELIG',
     ISNONTEXT: 'ER.IKKE.TEKST',
diff --git a/src/i18n/languages/deDE.ts b/src/i18n/languages/deDE.ts
index 38d97dc319..3de8ef765d 100644
--- a/src/i18n/languages/deDE.ts
+++ b/src/i18n/languages/deDE.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ISTFEHL',
     ISERROR: 'ISTFEHLER',
     ISEVEN: 'ISTGERADE',
+    ISFORMULA: 'ISTFORMEL',
     ISLOGICAL: 'ISTLOG',
     ISNA: 'ISTNV',
     ISNONTEXT: 'ISTKTEXT',
diff --git a/src/i18n/languages/enGB.ts b/src/i18n/languages/enGB.ts
index 8c10eedbe8..4765c7b808 100644
--- a/src/i18n/languages/enGB.ts
+++ b/src/i18n/languages/enGB.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ISERR',
     ISERROR: 'ISERROR',
     ISEVEN: 'ISEVEN',
+    ISFORMULA: 'ISFORMULA',
     ISLOGICAL: 'ISLOGICAL',
     ISNA: 'ISNA',
     ISNONTEXT: 'ISNONTEXT',
diff --git a/src/i18n/languages/esES.ts b/src/i18n/languages/esES.ts
index 183b913b10..0f48e7b96e 100644
--- a/src/i18n/languages/esES.ts
+++ b/src/i18n/languages/esES.ts
@@ -82,6 +82,7 @@ export const dictionary: RawTranslationPackage = {
     ISERR: 'ESERR',
     ISERROR: 'ESERROR',
     ISEVEN: 'ES.PAR',
+    ISFORMULA: 'ISFORMULA',
     ISLOGICAL: 'ESLOGICO',
     ISNA: 'ESNOD',
     ISNONTEXT: 'ESNOTEXTO',
diff --git a/src/i18n/languages/fiFI.ts b/src/i18n/languages/fiFI.ts
index c2ceefc3f2..dcb54d139a 100644
--- a/src/i18n/languages/fiFI.ts
+++ b/src/i18n/languages/fiFI.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ONVIRH',
     ISERROR: 'ONVIRHE',
     ISEVEN: 'ONPARILLINEN',
+    ISFORMULA: 'ONKAAVA',
     ISLOGICAL: 'ONTOTUUS',
     ISNA: 'ONPUUTTUU',
     ISNONTEXT: 'ONEI_TEKSTI',
diff --git a/src/i18n/languages/frFR.ts b/src/i18n/languages/frFR.ts
index e6fa7b17a8..7993c4a2e4 100644
--- a/src/i18n/languages/frFR.ts
+++ b/src/i18n/languages/frFR.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ESTERR',
     ISERROR: 'ESTERREUR',
     ISEVEN: 'EST.PAIR',
+    ISFORMULA: 'ESTFORMULE',
     ISLOGICAL: 'ESTLOGIQUE',
     ISNA: 'ESTNA',
     ISNONTEXT: 'ESTNONTEXTE',
diff --git a/src/i18n/languages/huHU.ts b/src/i18n/languages/huHU.ts
index 3e86a27c2e..9cac059907 100644
--- a/src/i18n/languages/huHU.ts
+++ b/src/i18n/languages/huHU.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'HIBA.E',
     ISERROR: 'HIBÁS',
     ISEVEN: 'PÁROSE',
+    ISFORMULA: 'KÉPLET',
     ISLOGICAL: 'LOGIKAI',
     ISNA: 'NINCS',
     ISNONTEXT: 'NEM.SZÖVEG',
diff --git a/src/i18n/languages/itIT.ts b/src/i18n/languages/itIT.ts
index a883ac5a17..c5b3581b66 100644
--- a/src/i18n/languages/itIT.ts
+++ b/src/i18n/languages/itIT.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'VAL.ERR',
     ISERROR: 'VAL.ERRORE',
     ISEVEN: 'VAL.PARI',
+    ISFORMULA: 'VAL.FORMULA',
     ISLOGICAL: 'VAL.LOGICO',
     ISNA: 'VAL.NON.DISP',
     ISNONTEXT: 'VAL.NON.TESTO',
diff --git a/src/i18n/languages/nbNO.ts b/src/i18n/languages/nbNO.ts
index 20bd3e345f..17def8c862 100644
--- a/src/i18n/languages/nbNO.ts
+++ b/src/i18n/languages/nbNO.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ERF',
     ISERROR: 'ERFEIL',
     ISEVEN: 'ERPARTALL',
+    ISFORMULA: 'ERFORMEL',
     ISLOGICAL: 'ERLOGISK',
     ISNA: 'ERIT',
     ISNONTEXT: 'ERIKKETEKST',
diff --git a/src/i18n/languages/nlNL.ts b/src/i18n/languages/nlNL.ts
index 9ccfc8b237..4011ec59a3 100644
--- a/src/i18n/languages/nlNL.ts
+++ b/src/i18n/languages/nlNL.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ISFOUT2',
     ISERROR: 'ISFOUT',
     ISEVEN: 'IS.EVEN',
+    ISFORMULA: 'ISFORMULE',
     ISLOGICAL: 'ISLOGISCH',
     ISNA: 'ISNB',
     ISNONTEXT: 'ISGEENTEKST',
diff --git a/src/i18n/languages/plPL.ts b/src/i18n/languages/plPL.ts
index 5016104c70..ca2620e801 100644
--- a/src/i18n/languages/plPL.ts
+++ b/src/i18n/languages/plPL.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'CZY.BŁ',
     ISERROR: 'CZY.BŁĄD',
     ISEVEN: 'CZY.PARZYSTE',
+    ISFORMULA: 'CZY.FORMUŁA',
     ISLOGICAL: 'CZY.LOGICZNA',
     ISNA: 'CZY.BRAK',
     ISNONTEXT: 'CZY.NIE.TEKST',
diff --git a/src/i18n/languages/ptPT.ts b/src/i18n/languages/ptPT.ts
index 58aa5f7f7b..14bcf08282 100644
--- a/src/i18n/languages/ptPT.ts
+++ b/src/i18n/languages/ptPT.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ÉERRO',
     ISERROR: 'ÉERROS',
     ISEVEN: 'ÉPAR',
+    ISFORMULA: 'ÉFÓRMULA',
     ISLOGICAL: 'ÉLÓGICO',
     ISNA: 'É.NÃO.DISP',
     ISNONTEXT: 'É.NÃO.TEXTO',
diff --git a/src/i18n/languages/ruRU.ts b/src/i18n/languages/ruRU.ts
index 3eb70bf07c..9fc40077f7 100644
--- a/src/i18n/languages/ruRU.ts
+++ b/src/i18n/languages/ruRU.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ЕОШ',
     ISERROR: 'ЕОШИБКА',
     ISEVEN: 'ЕЧЁТН',
+    ISFORMULA: 'ЕФОРМУЛА',
     ISLOGICAL: 'ЕЛОГИЧ',
     ISNA: 'ЕНД',
     ISNONTEXT: 'ЕНЕТЕКСТ',
diff --git a/src/i18n/languages/svSE.ts b/src/i18n/languages/svSE.ts
index f56b7ea9d5..0772955356 100644
--- a/src/i18n/languages/svSE.ts
+++ b/src/i18n/languages/svSE.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'ÄRF',
     ISERROR: 'ÄRFEL',
     ISEVEN: 'ÄRJÄMN',
+    ISFORMULA: 'ISFORMEL',
     ISLOGICAL: 'ÄRLOGISK',
     ISNA: 'ÄRSAKNAD',
     ISNONTEXT: 'ÄREJTEXT',
diff --git a/src/i18n/languages/trTR.ts b/src/i18n/languages/trTR.ts
index 5f1172c2ad..52ba9e478b 100644
--- a/src/i18n/languages/trTR.ts
+++ b/src/i18n/languages/trTR.ts
@@ -82,6 +82,7 @@ const dictionary: RawTranslationPackage = {
     ISERR: 'EHATA',
     ISERROR: 'EHATALIYSA',
     ISEVEN: 'ÇİFTMİ',
+    ISFORMULA: 'EFORMÜLSE',
     ISLOGICAL: 'EMANTIKSALSA',
     ISNA: 'EYOKSA',
     ISNONTEXT: 'EMETİNDEĞİLSE',
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 2ca5060f09..c84f79ccd7 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -9,6 +9,7 @@ import {Ast, AstNodeType, ProcedureAst} from '../../parser'
 import {InterpreterValue} from '../InterpreterValue'
 import {FunctionArgumentsDefinition, FunctionPlugin} from './FunctionPlugin'
 import {Maybe} from '../../Maybe'
+import {FormulaCellVertex, MatrixVertex} from '../../DependencyGraph'
 
 /**
  * Interpreter plugin containing information functions
@@ -52,6 +53,14 @@ export class InformationPlugin extends FunctionPlugin {
         ]
       }
     },
+    'ISFORMULA': {
+      method: 'isformula',
+      parameters: {
+        list: [
+          {argumentType: 'noerror'}
+        ]
+      }
+    },
     'ISNA': {
       method: 'isna',
       parameters: {
@@ -173,6 +182,25 @@ export class InformationPlugin extends FunctionPlugin {
     )
   }
 
+  /**
+   * Corresponds to ISFORMULA(value)
+   *
+   * Checks whether referenced cell is a formula
+   *
+   * @param ast
+   * @param formulaAddress
+   */
+  public isformula(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
+    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, this.parameters('ISFORMULA'),
+      () => new CellError(ErrorType.NA),
+      (reference: SimpleCellAddress) => {
+        const vertex = this.dependencyGraph.addressMapping.getCell(reference)
+        return vertex instanceof FormulaCellVertex || (vertex instanceof MatrixVertex && vertex.isFormula())
+      },
+      () => new CellError(ErrorType.NA)
+    )
+  }
+
   /**
    * Corresponds to ISBLANK(value)
    *
@@ -381,7 +409,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    * */
   public sheet(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, { list: [{argumentType: 'string'}] },
+    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, {list: [{argumentType: 'string'}]},
       () => formulaAddress.sheet + 1,
       (reference: SimpleCellAddress) => reference.sheet + 1,
       (value: string) => {
@@ -405,7 +433,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    * */
   public sheets(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, { list: [{argumentType: 'string'}] },
+    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, {list: [{argumentType: 'string'}]},
       () => this.dependencyGraph.sheetMapping.numberOfSheets(), // return number of sheets if no argument
       () => 1, // return 1 for valid reference
       () => new CellError(ErrorType.VALUE) // error otherwise
diff --git a/test/interpreter/function-isformula.spec.ts b/test/interpreter/function-isformula.spec.ts
new file mode 100644
index 0000000000..5508ad01e0
--- /dev/null
+++ b/test/interpreter/function-isformula.spec.ts
@@ -0,0 +1,49 @@
+import {ErrorType, HyperFormula} from '../../src'
+import {adr, detailedError} from '../testUtils'
+
+describe('Function ISFORMULA', () => {
+  it('should return true for cell with formula', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=A1', '=ISFORMULA(A1)']
+    ])
+
+    expect(engine.getCellValue(adr('B1'))).toEqual(true)
+  })
+
+  it('should return false for cell without formula', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['foo', '=ISFORMULA(A1)', '=ISFORMULA(A2)']
+    ])
+
+    expect(engine.getCellValue(adr('B1'))).toEqual(false)
+    expect(engine.getCellValue(adr('C1'))).toEqual(false)
+  })
+
+  it('should work with start of a range', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=A1', 2, '=ISFORMULA(A1:A2)', '=ISFORMULA(B1:B2)']
+    ])
+
+    expect(engine.getCellValue(adr('C1'))).toEqual(true)
+    expect(engine.getCellValue(adr('D1'))).toEqual(false)
+  })
+
+  it('should propagate error', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISFORMULA(1/0)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.DIV_BY_ZERO))
+  })
+
+  it('should return NA otherwise', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISFORMULA()', '=ISFORMULA(A1, A2)', '=ISFORMULA("foo")', '=ISFORMULA(42)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('B1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('C1'))).toEqual(detailedError(ErrorType.NA))
+    expect(engine.getCellValue(adr('D1'))).toEqual(detailedError(ErrorType.NA))
+  })
+})
\ No newline at end of file

From b29c173d889f33bf825c6f33138b535da64c7323 Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Sat, 25 Jul 2020 10:50:55 +0200
Subject: [PATCH 82/97] Function ISFORMULA should be able to check itself

---
 src/interpreter/plugin/InformationPlugin.ts | 3 ++-
 test/interpreter/function-isformula.spec.ts | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index c84f79ccd7..7560e4d43a 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -59,7 +59,8 @@ export class InformationPlugin extends FunctionPlugin {
         list: [
           {argumentType: 'noerror'}
         ]
-      }
+      },
+      doesNotNeedArgumentsToBeComputed: true
     },
     'ISNA': {
       method: 'isna',
diff --git a/test/interpreter/function-isformula.spec.ts b/test/interpreter/function-isformula.spec.ts
index 5508ad01e0..17730fc999 100644
--- a/test/interpreter/function-isformula.spec.ts
+++ b/test/interpreter/function-isformula.spec.ts
@@ -46,4 +46,12 @@ describe('Function ISFORMULA', () => {
     expect(engine.getCellValue(adr('C1'))).toEqual(detailedError(ErrorType.NA))
     expect(engine.getCellValue(adr('D1'))).toEqual(detailedError(ErrorType.NA))
   })
+
+  it('should work for itself', () => {
+    const engine = HyperFormula.buildFromArray([
+      ['=ISFORMULA(A1)']
+    ])
+
+    expect(engine.getCellValue(adr('A1'))).toEqual(true)
+  })
 })
\ No newline at end of file

From d494685f8d569bd7ff136284ff5c84cfcee7899c Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Thu, 30 Jul 2020 17:46:26 +0200
Subject: [PATCH 83/97] Refactor FORMULATEXT

---
 src/interpreter/plugin/FormulaTextPlugin.ts | 50 ++++++++-------------
 src/interpreter/plugin/FunctionPlugin.ts    | 36 ++++++++++++++-
 src/interpreter/plugin/InformationPlugin.ts | 34 --------------
 src/interpreter/plugin/index.ts             |  2 +-
 4 files changed, 55 insertions(+), 67 deletions(-)

diff --git a/src/interpreter/plugin/FormulaTextPlugin.ts b/src/interpreter/plugin/FormulaTextPlugin.ts
index 3d6fe35301..9c53141bb6 100644
--- a/src/interpreter/plugin/FormulaTextPlugin.ts
+++ b/src/interpreter/plugin/FormulaTextPlugin.ts
@@ -3,49 +3,37 @@
  * Copyright (c) 2020 Handsoncode. All rights reserved.
  */
 
-import {AstNodeType, ProcedureAst} from '../../parser'
+import {ProcedureAst} from '../../parser'
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {FunctionPlugin} from '../index'
-import {AbsoluteCellRange} from '../../AbsoluteCellRange'
-import {Maybe} from '../../Maybe'
 
 export class FormulaTextPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'FORMULATEXT': {
       method: 'formulatext',
+      parameters: {
+        list: [
+          {argumentType: 'noerror'}
+        ]
+      },
       doesNotNeedArgumentsToBeComputed: true,
       isDependentOnSheetStructureChange: true
     },
   }
 
+  /**
+   * Corresponds to FORMULATEXT(value)
+   *
+   * Returns a formula in a given cell as a string.
+   *
+   * @param ast
+   * @param formulaAddress
+   * */
   public formulatext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    if (ast.args.length !== 1) {
-      return new CellError(ErrorType.NA)
-    }
-
-    const arg = ast.args[0]
-
-    let cellReference: Maybe<SimpleCellAddress>
-
-    if (arg.type === AstNodeType.CELL_REFERENCE) {
-      cellReference = arg.reference.toSimpleCellAddress(formulaAddress)
-    } else if (arg.type === AstNodeType.CELL_RANGE || arg.type === AstNodeType.COLUMN_RANGE || arg.type === AstNodeType.ROW_RANGE) {
-      try {
-        cellReference = AbsoluteCellRange.fromAst(arg, formulaAddress).start
-      } catch (e) {
-        return new CellError(ErrorType.REF)
-      }
-    }
-
-    if (cellReference === undefined) {
-      const value = this.evaluateAst(arg, formulaAddress)
-      if (value instanceof CellError) {
-        return value
-      }
-      return new CellError(ErrorType.NA)
-    }
-
-    const formula = this.serialization.getCellFormula(cellReference)
-    return formula || new CellError(ErrorType.NA)
+    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, this.parameters('FORMULATEXT'),
+      () => new CellError(ErrorType.NA),
+      (cellReference: SimpleCellAddress) => this.serialization.getCellFormula(cellReference) || new CellError(ErrorType.NA),
+      () => new CellError(ErrorType.NA)
+    )
   }
 }
\ No newline at end of file
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 14235e3558..555e7adc12 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -9,7 +9,7 @@ import {ColumnSearchStrategy} from '../../ColumnSearch/ColumnSearchStrategy'
 import {Config} from '../../Config'
 import {DependencyGraph} from '../../DependencyGraph'
 import {Maybe} from '../../Maybe'
-import {Ast, ProcedureAst} from '../../parser'
+import {Ast, AstNodeType, ProcedureAst} from '../../parser'
 import {coerceScalarToBoolean, coerceScalarToString} from '../ArithmeticHelper'
 import {Interpreter} from '../Interpreter'
 import {InterpreterValue, SimpleRangeValue} from '../InterpreterValue'
@@ -207,6 +207,40 @@ export abstract class FunctionPlugin {
     return argCoerceFailure ?? fn(...coercedArguments)
   }
 
+  protected runFunctionWithReferenceArgument = (
+    args: Ast[],
+    formulaAddress: SimpleCellAddress,
+    argumentDefinitions: FunctionArgumentsDefinition,
+    noArgCallback: () => InternalScalarValue,
+    referenceCallback: (reference: SimpleCellAddress) => InternalScalarValue,
+    nonReferenceCallback: (...arg: any) => InternalScalarValue
+  ) => {
+    if (args.length === 0) {
+      return noArgCallback()
+    } else if (args.length > 1) {
+      return new CellError(ErrorType.NA)
+    }
+    const arg = args[0]
+
+    let cellReference: Maybe<SimpleCellAddress>
+
+    if (arg.type === AstNodeType.CELL_REFERENCE) {
+      cellReference = arg.reference.toSimpleCellAddress(formulaAddress)
+    } else if (arg.type === AstNodeType.CELL_RANGE || arg.type === AstNodeType.COLUMN_RANGE || arg.type === AstNodeType.ROW_RANGE) {
+      try {
+        cellReference = AbsoluteCellRange.fromAst(arg, formulaAddress).start
+      } catch (e) {
+        return new CellError(ErrorType.REF)
+      }
+    }
+
+    if (cellReference !== undefined) {
+      return referenceCallback(cellReference)
+    }
+
+    return this.runFunction(args, formulaAddress, argumentDefinitions, nonReferenceCallback)
+  }
+
   protected parameters(name: string): FunctionArgumentsDefinition {
     const params = (this.constructor as FunctionPluginDefinition).implementedFunctions[name]?.parameters
     if (params !== undefined) {
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 7560e4d43a..958284379e 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -440,38 +440,4 @@ export class InformationPlugin extends FunctionPlugin {
       () => new CellError(ErrorType.VALUE) // error otherwise
     )
   }
-
-  protected runFunctionWithReferenceArgument = (
-    args: Ast[],
-    formulaAddress: SimpleCellAddress,
-    argumentDefinitions: FunctionArgumentsDefinition,
-    noArgCallback: () => InternalScalarValue,
-    referenceCallback: (reference: SimpleCellAddress) => InternalScalarValue,
-    nonReferenceCallback: (...arg: any) => InternalScalarValue
-  ) => {
-    if (args.length === 0) {
-      return noArgCallback()
-    } else if (args.length > 1) {
-      return new CellError(ErrorType.NA)
-    }
-    const arg = args[0]
-
-    let cellReference: Maybe<SimpleCellAddress>
-
-    if (arg.type === AstNodeType.CELL_REFERENCE) {
-      cellReference = arg.reference.toSimpleCellAddress(formulaAddress)
-    } else if (arg.type === AstNodeType.CELL_RANGE || arg.type === AstNodeType.COLUMN_RANGE || arg.type === AstNodeType.ROW_RANGE) {
-      try {
-        cellReference = AbsoluteCellRange.fromAst(arg, formulaAddress).start
-      } catch (e) {
-        return new CellError(ErrorType.REF)
-      }
-    }
-
-    if (cellReference !== undefined) {
-      return referenceCallback(cellReference)
-    }
-
-    return this.runFunction(args, formulaAddress, argumentDefinitions, nonReferenceCallback)
-  }
 }
diff --git a/src/interpreter/plugin/index.ts b/src/interpreter/plugin/index.ts
index 6d84e997a1..b26299efb9 100644
--- a/src/interpreter/plugin/index.ts
+++ b/src/interpreter/plugin/index.ts
@@ -37,4 +37,4 @@ export {CharPlugin} from './CharPlugin'
 export {CodePlugin} from './CodePlugin'
 export {ErrorFunctionPlugin} from './ErrorFunctionPlugin'
 export {CorrelPlugin} from './CorrelPlugin'
-export {FormulaTextPlugin} from './FormulaTextPlugin'
\ No newline at end of file
+export {FormulaTextPlugin} from './FormulaTextPlugin'

From ae1e08fd8f4948250bd70bb8f2f98410c372acad Mon Sep 17 00:00:00 2001
From: Jakub Kowalski <kowalski_jakub@hotmail.com>
Date: Thu, 30 Jul 2020 17:46:56 +0200
Subject: [PATCH 84/97] Changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a8a2879d1..5dc9324425 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added helper methods for keeping track of cell/range dependencies: getCellPrecedents and getCellDependents. (#441)
 - Added 4 financial functions FV, PMT, PPMT, IPMT.
 - Added FORMULATEXT function.
+- Added 8 information functions ISERR, ISNA, ISREF, NA, SHEET, SHEETS, ISBINARY, ISFORMULA
 
 ### Changed
 - Operation `moveCells` creating cyclic dependencies does not cause losing original formula. (#479)

From 481f1da415e1538379b0175cdc37e4c69e60131a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Thu, 30 Jul 2020 22:31:16 +0200
Subject: [PATCH 85/97] Update CHANGELOG.md

Co-authored-by: Wojciech Czerniak <wojciech.czerniak@gmail.com>
---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a8a2879d1..c30eef4e3f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,7 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 - Operation `moveCells` creating cyclic dependencies does not cause losing original formula. (#479)
-- Simplified adding new function modules, reworked (simplified) implementations of existing modules.
+- Simplified adding new function modules, reworked (simplified) implementations of existing modules. (#480)
 
 ### Fixed
 - Fixed hardcoding of languages in i18n tests. (#471)

From 90ee8a0a270bc44f9330f1667270a9a6ca898eed Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 30 Jul 2020 23:34:13 +0200
Subject: [PATCH 86/97] enum

---
 src/interpreter/plugin/AbsPlugin.ts           |  4 +-
 src/interpreter/plugin/BitShiftPlugin.ts      | 10 ++--
 .../plugin/BitwiseLogicOperationsPlugin.ts    | 14 +++---
 src/interpreter/plugin/BooleanPlugin.ts       | 34 +++++++-------
 src/interpreter/plugin/CharPlugin.ts          |  4 +-
 src/interpreter/plugin/CodePlugin.ts          |  4 +-
 src/interpreter/plugin/CountUniquePlugin.ts   |  4 +-
 src/interpreter/plugin/DatePlugin.ts          | 26 +++++------
 src/interpreter/plugin/DegreesPlugin.ts       |  4 +-
 src/interpreter/plugin/DeltaPlugin.ts         |  6 +--
 src/interpreter/plugin/ErrorFunctionPlugin.ts |  8 ++--
 src/interpreter/plugin/ExpPlugin.ts           |  4 +-
 src/interpreter/plugin/FinancialPlugin.ts     | 46 +++++++++----------
 src/interpreter/plugin/FunctionPlugin.ts      | 34 ++++++++------
 src/interpreter/plugin/InformationPlugin.ts   | 14 +++---
 src/interpreter/plugin/IsEvenPlugin.ts        |  4 +-
 src/interpreter/plugin/IsOddPlugin.ts         |  4 +-
 src/interpreter/plugin/LogarithmPlugin.ts     | 10 ++--
 src/interpreter/plugin/MedianPlugin.ts        |  4 +-
 src/interpreter/plugin/ModuloPlugin.ts        |  6 +--
 src/interpreter/plugin/PowerPlugin.ts         |  6 +--
 src/interpreter/plugin/RadiansPlugin.ts       |  4 +-
 .../plugin/RadixConversionPlugin.ts           | 34 +++++++-------
 src/interpreter/plugin/RoundingPlugin.ts      | 30 ++++++------
 src/interpreter/plugin/SqrtPlugin.ts          |  4 +-
 src/interpreter/plugin/TextPlugin.ts          | 40 ++++++++--------
 src/interpreter/plugin/TrigonometryPlugin.ts  | 20 ++++----
 test/optional-parameters.spec.ts              | 12 ++---
 28 files changed, 200 insertions(+), 194 deletions(-)

diff --git a/src/interpreter/plugin/AbsPlugin.ts b/src/interpreter/plugin/AbsPlugin.ts
index 078353f23c..527e3a3e3d 100644
--- a/src/interpreter/plugin/AbsPlugin.ts
+++ b/src/interpreter/plugin/AbsPlugin.ts
@@ -5,14 +5,14 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class AbsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ABS': {
       method: 'abs',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]}
     },
   }
diff --git a/src/interpreter/plugin/BitShiftPlugin.ts b/src/interpreter/plugin/BitShiftPlugin.ts
index 135bd8d23f..8629180b24 100644
--- a/src/interpreter/plugin/BitShiftPlugin.ts
+++ b/src/interpreter/plugin/BitShiftPlugin.ts
@@ -5,7 +5,7 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 const MAX_48BIT_INTEGER = 281474976710655
 const SHIFT_MIN_POSITIONS = -53
@@ -16,15 +16,15 @@ export class BitShiftPlugin extends FunctionPlugin {
     'BITLSHIFT': {
       method: 'bitlshift',
       parameters: { list: [
-        { argumentType: 'integer', minValue: 0 },
-        { argumentType: 'integer', minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
+        { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
+        { argumentType: ArgumentTypes.INTEGER, minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
       ]}
     },
     'BITRSHIFT': {
       method: 'bitrshift',
       parameters: { list: [
-        { argumentType: 'integer', minValue: 0 },
-        { argumentType: 'integer', minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
+        { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
+        { argumentType: ArgumentTypes.INTEGER, minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
       ]}
     },
   }
diff --git a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
index f3c04fbfe3..2c5ff5e654 100644
--- a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
+++ b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
@@ -5,29 +5,29 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class BitwiseLogicOperationsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'BITAND': {
       method: 'bitand',
       parameters: { list: [
-        { argumentType: 'integer', minValue: 0 },
-        { argumentType: 'integer', minValue: 0 },
+        { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
+        { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
       ]}
     },
     'BITOR': {
       method: 'bitor',
       parameters: { list: [
-        { argumentType: 'integer', minValue: 0 },
-        { argumentType: 'integer', minValue: 0 },
+        { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
+        { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
       ]}
     },
     'BITXOR': {
       method: 'bitxor',
       parameters: { list: [
-        { argumentType: 'integer', minValue: 0 },
-        { argumentType: 'integer', minValue: 0 },
+        { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
+        { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
       ]}
     },
   }
diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index 6ed398342c..a78f5eb6b4 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -6,7 +6,7 @@
 import {CellError, ErrorType, InternalNoErrorCellValue, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
 import {InterpreterValue} from '../InterpreterValue'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 /**
  * Interpreter plugin containing boolean functions
@@ -25,9 +25,9 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'conditionalIf',
       parameters: {
         list: [
-          {argumentType: 'boolean'},
-          {argumentType: 'scalar'},
-          {argumentType: 'scalar', defaultValue: false},
+          {argumentType: ArgumentTypes.BOOLEAN},
+          {argumentType: ArgumentTypes.SCALAR},
+          {argumentType: ArgumentTypes.SCALAR, defaultValue: false},
         ]
       },
     },
@@ -35,7 +35,7 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'and',
       parameters: {
         list: [
-          {argumentType: 'boolean'},
+          {argumentType: ArgumentTypes.BOOLEAN},
         ],
         repeatedArg: true,
         expandRanges: true,
@@ -45,7 +45,7 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'or',
       parameters: {
         list: [
-          {argumentType: 'boolean'},
+          {argumentType: ArgumentTypes.BOOLEAN},
         ],
         repeatedArg: true,
         expandRanges: true,
@@ -55,7 +55,7 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'xor',
       parameters: {
         list: [
-          {argumentType: 'boolean'},
+          {argumentType: ArgumentTypes.BOOLEAN},
         ],
         repeatedArg: true,
         expandRanges: true,
@@ -65,7 +65,7 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'not',
       parameters: {
         list: [
-          {argumentType: 'boolean'},
+          {argumentType: ArgumentTypes.BOOLEAN},
         ]
       },
     },
@@ -73,9 +73,9 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'switch',
       parameters: {
         list: [
-          {argumentType: 'noerror'},
-          {argumentType: 'scalar'},
-          {argumentType: 'scalar'},
+          {argumentType: ArgumentTypes.NOERROR},
+          {argumentType: ArgumentTypes.SCALAR},
+          {argumentType: ArgumentTypes.SCALAR},
         ],
         repeatedArg: true,
       },
@@ -84,8 +84,8 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'iferror',
       parameters: {
         list: [
-          {argumentType: 'scalar'},
-          {argumentType: 'scalar'},
+          {argumentType: ArgumentTypes.SCALAR},
+          {argumentType: ArgumentTypes.SCALAR},
         ]
       },
     },
@@ -93,8 +93,8 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'ifna',
       parameters: {
         list: [
-          {argumentType: 'scalar'},
-          {argumentType: 'scalar'},
+          {argumentType: ArgumentTypes.SCALAR},
+          {argumentType: ArgumentTypes.SCALAR},
         ]
       },
     },
@@ -102,8 +102,8 @@ export class BooleanPlugin extends FunctionPlugin {
       method: 'choose',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'scalar'},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.SCALAR},
         ],
         repeatedArg: true,
       },
diff --git a/src/interpreter/plugin/CharPlugin.ts b/src/interpreter/plugin/CharPlugin.ts
index 3e4f318307..ddf44af14e 100644
--- a/src/interpreter/plugin/CharPlugin.ts
+++ b/src/interpreter/plugin/CharPlugin.ts
@@ -5,7 +5,7 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class CharPlugin extends FunctionPlugin {
   public static implementedFunctions = {
@@ -13,7 +13,7 @@ export class CharPlugin extends FunctionPlugin {
       method: 'char',
       parameters: {
         list: [
-          {argumentType: 'number'}
+          {argumentType: ArgumentTypes.NUMBER}
         ],
       }
     },
diff --git a/src/interpreter/plugin/CodePlugin.ts b/src/interpreter/plugin/CodePlugin.ts
index 62ecfa1023..3c39809f06 100644
--- a/src/interpreter/plugin/CodePlugin.ts
+++ b/src/interpreter/plugin/CodePlugin.ts
@@ -5,7 +5,7 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class CodePlugin extends FunctionPlugin {
   public static implementedFunctions = {
@@ -13,7 +13,7 @@ export class CodePlugin extends FunctionPlugin {
       method: 'code',
       parameters: {
         list: [
-          {argumentType: 'string'}
+          {argumentType: ArgumentTypes.STRING}
         ]
       },
     },
diff --git a/src/interpreter/plugin/CountUniquePlugin.ts b/src/interpreter/plugin/CountUniquePlugin.ts
index e20965f3eb..4d469ed26b 100644
--- a/src/interpreter/plugin/CountUniquePlugin.ts
+++ b/src/interpreter/plugin/CountUniquePlugin.ts
@@ -5,7 +5,7 @@
 
 import {CellError, EmptyValueType, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 /**
  * Interpreter plugin containing COUNTUNIQUE function
@@ -16,7 +16,7 @@ export class CountUniquePlugin extends FunctionPlugin {
       method: 'countunique',
       parameters: {
         list: [
-          {argumentType: 'scalar'},
+          {argumentType: ArgumentTypes.SCALAR},
         ],
         repeatedArg: true,
         expandRanges: true,
diff --git a/src/interpreter/plugin/DatePlugin.ts b/src/interpreter/plugin/DatePlugin.ts
index ef17248886..6db1939e3d 100644
--- a/src/interpreter/plugin/DatePlugin.ts
+++ b/src/interpreter/plugin/DatePlugin.ts
@@ -8,7 +8,7 @@ import {endOfMonth, offsetMonth} from '../../DateTimeHelper'
 import {format} from '../../format/format'
 import {AstNodeType, ProcedureAst} from '../../parser'
 import {SimpleRangeValue} from '../InterpreterValue'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 /**
  * Interpreter plugin containing date-specific functions
@@ -19,9 +19,9 @@ export class DatePlugin extends FunctionPlugin {
       method: 'date',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number'},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
         ]
       },
     },
@@ -29,7 +29,7 @@ export class DatePlugin extends FunctionPlugin {
       method: 'month',
       parameters: {
         list: [
-          {argumentType: 'number'},
+          {argumentType: ArgumentTypes.NUMBER},
         ]
       },
     },
@@ -37,7 +37,7 @@ export class DatePlugin extends FunctionPlugin {
       method: 'year',
       parameters: {
         list: [
-          {argumentType: 'number'},
+          {argumentType: ArgumentTypes.NUMBER},
         ]
       },
     },
@@ -45,8 +45,8 @@ export class DatePlugin extends FunctionPlugin {
       method: 'text',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'string'},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.STRING},
         ]
       },
     },
@@ -54,8 +54,8 @@ export class DatePlugin extends FunctionPlugin {
       method: 'eomonth',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number'},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
         ]
       },
     },
@@ -63,7 +63,7 @@ export class DatePlugin extends FunctionPlugin {
       method: 'day',
       parameters: {
         list: [
-          {argumentType: 'number'},
+          {argumentType: ArgumentTypes.NUMBER},
         ]
       },
     },
@@ -71,8 +71,8 @@ export class DatePlugin extends FunctionPlugin {
       method: 'days',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number'},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
         ]
       },
     },
diff --git a/src/interpreter/plugin/DegreesPlugin.ts b/src/interpreter/plugin/DegreesPlugin.ts
index 05c82c4de5..b1e428b366 100644
--- a/src/interpreter/plugin/DegreesPlugin.ts
+++ b/src/interpreter/plugin/DegreesPlugin.ts
@@ -5,7 +5,7 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class DegreesPlugin extends FunctionPlugin {
   public static implementedFunctions = {
@@ -13,7 +13,7 @@ export class DegreesPlugin extends FunctionPlugin {
       method: 'degrees',
       parameters: {
         list: [
-          {argumentType: 'number'}
+          {argumentType: ArgumentTypes.NUMBER}
         ]
       },
     },
diff --git a/src/interpreter/plugin/DeltaPlugin.ts b/src/interpreter/plugin/DeltaPlugin.ts
index 5ecba964a5..96bd936da0 100644
--- a/src/interpreter/plugin/DeltaPlugin.ts
+++ b/src/interpreter/plugin/DeltaPlugin.ts
@@ -5,7 +5,7 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class DeltaPlugin extends FunctionPlugin {
   public static implementedFunctions = {
@@ -13,8 +13,8 @@ export class DeltaPlugin extends FunctionPlugin {
       method: 'delta',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number', defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
       },
     },
diff --git a/src/interpreter/plugin/ErrorFunctionPlugin.ts b/src/interpreter/plugin/ErrorFunctionPlugin.ts
index d5930243ad..f4cfa362f1 100644
--- a/src/interpreter/plugin/ErrorFunctionPlugin.ts
+++ b/src/interpreter/plugin/ErrorFunctionPlugin.ts
@@ -5,7 +5,7 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class ErrorFunctionPlugin extends FunctionPlugin {
   public static implementedFunctions = {
@@ -13,8 +13,8 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
       method: 'erf',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number', optionalArg: true},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER, optionalArg: true},
         ]
       },
     },
@@ -22,7 +22,7 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
       method: 'erfc',
       parameters: {
         list: [
-          {argumentType: 'number'}
+          {argumentType: ArgumentTypes.NUMBER}
         ]
       },
     },
diff --git a/src/interpreter/plugin/ExpPlugin.ts b/src/interpreter/plugin/ExpPlugin.ts
index 7350cbfbc5..cfe3a97e9a 100644
--- a/src/interpreter/plugin/ExpPlugin.ts
+++ b/src/interpreter/plugin/ExpPlugin.ts
@@ -5,14 +5,14 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class ExpPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'EXP': {
       method: 'exp',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]},
     },
   }
diff --git a/src/interpreter/plugin/FinancialPlugin.ts b/src/interpreter/plugin/FinancialPlugin.ts
index 5f98e39f0f..c3e033e554 100644
--- a/src/interpreter/plugin/FinancialPlugin.ts
+++ b/src/interpreter/plugin/FinancialPlugin.ts
@@ -5,7 +5,7 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class FinancialPlugin extends FunctionPlugin {
   public static implementedFunctions = {
@@ -13,11 +13,11 @@ export class FinancialPlugin extends FunctionPlugin {
       method: 'pmt',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number', defaultValue: 0},
-          {argumentType: 'number', defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
       },
     },
@@ -25,12 +25,12 @@ export class FinancialPlugin extends FunctionPlugin {
       method: 'ipmt',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number', defaultValue: 0},
-          {argumentType: 'number', defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
       },
     },
@@ -38,12 +38,12 @@ export class FinancialPlugin extends FunctionPlugin {
       method: 'ppmt',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number', defaultValue: 0},
-          {argumentType: 'number', defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
       },
     },
@@ -51,11 +51,11 @@ export class FinancialPlugin extends FunctionPlugin {
       method: 'fv',
       parameters: {
         list: [
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number'},
-          {argumentType: 'number', defaultValue: 0},
-          {argumentType: 'number', defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
       },
     },
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 14235e3558..737b1f995f 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -33,7 +33,15 @@ export interface FunctionPluginDefinition {
   implementedFunctions: ImplementedFunctions,
 }
 
-export type ArgumentTypes = 'string' | 'number' | 'boolean' | 'scalar' | 'noerror' | 'range' | 'integer'
+export enum ArgumentTypes {
+  STRING = 'STRING',
+  NUMBER = 'NUMBER',
+  BOOLEAN = 'BOOLEAN',
+  SCALAR = 'scalar',
+  NOERROR = 'noerror',
+  RANGE = 'range',
+  INTEGER = 'integer',
+}
 
 export interface FunctionArgumentsDefinition {
   list: FunctionArgument[],
@@ -42,7 +50,7 @@ export interface FunctionArgumentsDefinition {
 }
 
 export interface FunctionArgument {
-  argumentType: string,
+  argumentType: ArgumentTypes,
   defaultValue?: InternalScalarValue,
   optionalArg?: boolean,
   minValue?: number,
@@ -110,15 +118,15 @@ export abstract class FunctionPlugin {
 
   public coerceToType(arg: InterpreterValue, coercedType: FunctionArgument): Maybe<InterpreterValue> {
     if(arg instanceof SimpleRangeValue) {
-      if(coercedType.argumentType === 'range') {
+      if(coercedType.argumentType === ArgumentTypes.RANGE) {
         return arg
       } else {
         return undefined
       }
     } else {
-      switch (coercedType.argumentType as ArgumentTypes) {
-        case 'integer':
-        case 'number':
+      switch (coercedType.argumentType) {
+        case ArgumentTypes.INTEGER:
+        case ArgumentTypes.NUMBER:
           // eslint-disable-next-line no-case-declarations
           const value = this.coerceScalarToNumberOrError(arg)
           if(typeof value !== 'number') {
@@ -136,19 +144,19 @@ export abstract class FunctionPlugin {
           if (coercedType.greaterThan !== undefined && value <= coercedType.greaterThan) {
             return new CellError(ErrorType.NUM)
           }
-          if(coercedType.argumentType === 'integer' && !Number.isInteger(value)) {
+          if(coercedType.argumentType === ArgumentTypes.INTEGER && !Number.isInteger(value)) {
             return new CellError(ErrorType.NUM)
           }
           return value
-        case 'string':
+        case ArgumentTypes.STRING:
           return coerceScalarToString(arg)
-        case 'boolean':
+        case ArgumentTypes.BOOLEAN:
           return coerceScalarToBoolean(arg)
-        case 'scalar':
+        case ArgumentTypes.SCALAR:
           return arg
-        case 'noerror':
+        case ArgumentTypes.NOERROR:
           return arg
-        case 'range':
+        case ArgumentTypes.RANGE:
           return undefined
       }
     }
@@ -192,7 +200,7 @@ export abstract class FunctionPlugin {
         //we apply coerce only to non-default values
         const coercedArg = val !== undefined ? this.coerceToType(arg, argumentDefinitions[j]) : arg
         if(coercedArg !== undefined) {
-          if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== 'scalar') {
+          if (coercedArg instanceof CellError && argumentDefinitions[j].argumentType !== ArgumentTypes.SCALAR) {
             //if this is first error encountered, store it
             argCoerceFailure = argCoerceFailure ?? coercedArg
           }
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index ff5f4a1049..b4deaa3f9b 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -7,7 +7,7 @@ import {AbsoluteCellRange} from '../../AbsoluteCellRange'
 import {CellError, EmptyValue, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {AstNodeType, ProcedureAst} from '../../parser'
 import {InterpreterValue} from '../InterpreterValue'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 /**
  * Interpreter plugin containing information functions
@@ -17,37 +17,37 @@ export class InformationPlugin extends FunctionPlugin {
     'ISERROR': {
       method: 'iserror',
       parameters: { list: [
-        { argumentType: 'scalar'}
+        { argumentType: ArgumentTypes.SCALAR}
       ]}
     },
     'ISBLANK': {
       method: 'isblank',
       parameters: { list: [
-        { argumentType: 'scalar'}
+        { argumentType: ArgumentTypes.SCALAR}
       ]}
     },
     'ISNUMBER': {
       method: 'isnumber',
       parameters: { list: [
-        { argumentType: 'scalar'}
+        { argumentType: ArgumentTypes.SCALAR}
       ]}
     },
     'ISLOGICAL': {
       method: 'islogical',
       parameters: { list: [
-        { argumentType: 'scalar'}
+        { argumentType: ArgumentTypes.SCALAR}
       ]}
     },
     'ISTEXT': {
       method: 'istext',
       parameters: { list: [
-        { argumentType: 'scalar'}
+        { argumentType: ArgumentTypes.SCALAR}
       ]}
     },
     'ISNONTEXT': {
       method: 'isnontext',
       parameters: { list: [
-        { argumentType: 'scalar'}
+        { argumentType: ArgumentTypes.SCALAR}
       ]}
     },
     'COLUMNS': {
diff --git a/src/interpreter/plugin/IsEvenPlugin.ts b/src/interpreter/plugin/IsEvenPlugin.ts
index f8154d7b4e..67a3432d49 100644
--- a/src/interpreter/plugin/IsEvenPlugin.ts
+++ b/src/interpreter/plugin/IsEvenPlugin.ts
@@ -5,14 +5,14 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class IsEvenPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISEVEN': {
       method: 'iseven',
       parameters: { list: [
-        { argumentType: 'number'}
+        { argumentType: ArgumentTypes.NUMBER}
       ]}
     },
   }
diff --git a/src/interpreter/plugin/IsOddPlugin.ts b/src/interpreter/plugin/IsOddPlugin.ts
index 9398305409..3e307575b3 100644
--- a/src/interpreter/plugin/IsOddPlugin.ts
+++ b/src/interpreter/plugin/IsOddPlugin.ts
@@ -5,7 +5,7 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class IsOddPlugin extends FunctionPlugin {
   public static implementedFunctions = {
@@ -13,7 +13,7 @@ export class IsOddPlugin extends FunctionPlugin {
       method: 'isodd',
       parameters: {
         list: [
-          {argumentType: 'number'}
+          {argumentType: ArgumentTypes.NUMBER}
         ]
       }
     },
diff --git a/src/interpreter/plugin/LogarithmPlugin.ts b/src/interpreter/plugin/LogarithmPlugin.ts
index dafbbacd87..8346b4a22d 100644
--- a/src/interpreter/plugin/LogarithmPlugin.ts
+++ b/src/interpreter/plugin/LogarithmPlugin.ts
@@ -5,7 +5,7 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class LogarithmPlugin extends FunctionPlugin {
 
@@ -14,7 +14,7 @@ export class LogarithmPlugin extends FunctionPlugin {
       method: 'log10',
       parameters: {
         list: [
-          {argumentType: 'number'}
+          {argumentType: ArgumentTypes.NUMBER}
         ]
       },
     },
@@ -22,8 +22,8 @@ export class LogarithmPlugin extends FunctionPlugin {
       method: 'log',
       parameters: {
         list: [
-          {argumentType: 'number', greaterThan: 0},
-          {argumentType: 'number', defaultValue: 10, greaterThan: 0},
+          {argumentType: ArgumentTypes.NUMBER, greaterThan: 0},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 10, greaterThan: 0},
         ]
       },
     },
@@ -31,7 +31,7 @@ export class LogarithmPlugin extends FunctionPlugin {
       method: 'ln',
       parameters: {
         list: [
-          {argumentType: 'number'}
+          {argumentType: ArgumentTypes.NUMBER}
         ]
       },
     },
diff --git a/src/interpreter/plugin/MedianPlugin.ts b/src/interpreter/plugin/MedianPlugin.ts
index 4163ba09aa..9c43727e5b 100644
--- a/src/interpreter/plugin/MedianPlugin.ts
+++ b/src/interpreter/plugin/MedianPlugin.ts
@@ -5,7 +5,7 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 /**
  * Interpreter plugin containing MEDIAN function
@@ -17,7 +17,7 @@ export class MedianPlugin extends FunctionPlugin {
       method: 'median',
       parameters: {
         list: [
-          {argumentType: 'noerror'},
+          {argumentType: ArgumentTypes.NOERROR},
         ],
         repeatedArg: true,
         expandRanges: true,
diff --git a/src/interpreter/plugin/ModuloPlugin.ts b/src/interpreter/plugin/ModuloPlugin.ts
index cae4bcdbcd..e91a1ebc69 100644
--- a/src/interpreter/plugin/ModuloPlugin.ts
+++ b/src/interpreter/plugin/ModuloPlugin.ts
@@ -5,15 +5,15 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class ModuloPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'MOD': {
       method: 'mod',
       parameters: { list: [
-        { argumentType: 'number' },
-        { argumentType: 'number' },
+        { argumentType: ArgumentTypes.NUMBER },
+        { argumentType: ArgumentTypes.NUMBER },
       ]},
     },
   }
diff --git a/src/interpreter/plugin/PowerPlugin.ts b/src/interpreter/plugin/PowerPlugin.ts
index 59ed57f72e..6d5b4cf5a9 100644
--- a/src/interpreter/plugin/PowerPlugin.ts
+++ b/src/interpreter/plugin/PowerPlugin.ts
@@ -5,15 +5,15 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class PowerPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'POWER': {
       method: 'power',
       parameters: { list: [
-        { argumentType: 'number' },
-        { argumentType: 'number' },
+        { argumentType: ArgumentTypes.NUMBER },
+        { argumentType: ArgumentTypes.NUMBER },
       ]},
     },
   }
diff --git a/src/interpreter/plugin/RadiansPlugin.ts b/src/interpreter/plugin/RadiansPlugin.ts
index ac0af90e0d..ed12a09c84 100644
--- a/src/interpreter/plugin/RadiansPlugin.ts
+++ b/src/interpreter/plugin/RadiansPlugin.ts
@@ -5,14 +5,14 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class RadiansPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'RADIANS': {
       method: 'radians',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]},
     },
   }
diff --git a/src/interpreter/plugin/RadixConversionPlugin.ts b/src/interpreter/plugin/RadixConversionPlugin.ts
index 2bb0235298..ea6b9891b1 100644
--- a/src/interpreter/plugin/RadixConversionPlugin.ts
+++ b/src/interpreter/plugin/RadixConversionPlugin.ts
@@ -7,7 +7,7 @@ import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../.
 import {padLeft} from '../../format/format'
 import {Maybe} from '../../Maybe'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 const NUMBER_OF_BITS = 10
 const DECIMAL_NUMBER_OF_BITS = 255
@@ -20,57 +20,57 @@ export class RadixConversionPlugin extends FunctionPlugin {
     'DEC2BIN': {
       method: 'dec2bin',
       parameters: { list: [
-        { argumentType: 'number', minValue: minValFromBase(2), maxValue: maxValFromBase(2) },
-        { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
+        { argumentType: ArgumentTypes.NUMBER, minValue: minValFromBase(2), maxValue: maxValFromBase(2) },
+        { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 1, maxValue: 10 },
       ]},
     },
     'DEC2OCT': {
       method: 'dec2oct',
       parameters: { list: [
-        { argumentType: 'number', minValue: minValFromBase(8), maxValue: maxValFromBase(8) },
-        { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
+        { argumentType: ArgumentTypes.NUMBER, minValue: minValFromBase(8), maxValue: maxValFromBase(8) },
+        { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 1, maxValue: 10 },
       ]},
     },
     'DEC2HEX': {
       method: 'dec2hex',
       parameters: { list: [
-        { argumentType: 'number', minValue: minValFromBase(16), maxValue: maxValFromBase(16) },
-        { argumentType: 'number', optionalArg: true, minValue: 1, maxValue: 10 },
+        { argumentType: ArgumentTypes.NUMBER, minValue: minValFromBase(16), maxValue: maxValFromBase(16) },
+        { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 1, maxValue: 10 },
       ]},
     },
     'BIN2DEC': {
       method: 'bin2dec',
       parameters: { list: [
-        { argumentType: 'string' }
+        { argumentType: ArgumentTypes.STRING }
       ]},
     },
     'BIN2OCT': {
       method: 'bin2oct',
       parameters: { list: [
-        { argumentType: 'string' },
-        { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
+        { argumentType: ArgumentTypes.STRING },
+        { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
       ]},
     },
     'BIN2HEX': {
       method: 'bin2hex',
       parameters: { list: [
-        { argumentType: 'string' },
-        { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
+        { argumentType: ArgumentTypes.STRING },
+        { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
       ]},
     },
     'DECIMAL': {
       method: 'decimal',
       parameters: { list: [
-        { argumentType: 'string' },
-        { argumentType: 'number', minValue: MIN_BASE, maxValue: MAX_BASE },
+        { argumentType: ArgumentTypes.STRING },
+        { argumentType: ArgumentTypes.NUMBER, minValue: MIN_BASE, maxValue: MAX_BASE },
       ]},
     },
     'BASE': {
       method: 'base',
       parameters: { list: [
-        { argumentType: 'number', minValue: 0 },
-        { argumentType: 'number', minValue: MIN_BASE, maxValue: MAX_BASE },
-        { argumentType: 'number', optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
+        { argumentType: ArgumentTypes.NUMBER, minValue: 0 },
+        { argumentType: ArgumentTypes.NUMBER, minValue: MIN_BASE, maxValue: MAX_BASE },
+        { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
       ]},
     },
   }
diff --git a/src/interpreter/plugin/RoundingPlugin.ts b/src/interpreter/plugin/RoundingPlugin.ts
index 6ffa0c2444..d60e040538 100644
--- a/src/interpreter/plugin/RoundingPlugin.ts
+++ b/src/interpreter/plugin/RoundingPlugin.ts
@@ -5,7 +5,7 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export function findNextOddNumber(arg: number): number {
   const ceiled = Math.ceil(arg)
@@ -22,55 +22,55 @@ export class RoundingPlugin extends FunctionPlugin {
     'ROUNDUP': {
       method: 'roundup',
       parameters: { list: [
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0},
+        { argumentType: ArgumentTypes.NUMBER },
+        { argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
       ]},
     },
     'ROUNDDOWN': {
       method: 'rounddown',
       parameters: { list: [
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0},
+        { argumentType: ArgumentTypes.NUMBER },
+        { argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
       ]},
     },
     'ROUND': {
       method: 'round',
       parameters: { list: [
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0},
+        { argumentType: ArgumentTypes.NUMBER },
+        { argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
       ]},
     },
     'TRUNC': {
       method: 'trunc',
       parameters: { list: [
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 0},
+        { argumentType: ArgumentTypes.NUMBER },
+        { argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
       ]},
     },
     'INT': {
       method: 'intFunc',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]},
     },
     'EVEN': {
       method: 'even',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]},
     },
     'ODD': {
       method: 'odd',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]},
     },
     'CEILING': {
       method: 'ceiling',
       parameters: { list: [
-        { argumentType: 'number' },
-        { argumentType: 'number', defaultValue: 1 },
-        { argumentType: 'number', defaultValue: 0 },
+        { argumentType: ArgumentTypes.NUMBER },
+        { argumentType: ArgumentTypes.NUMBER, defaultValue: 1 },
+        { argumentType: ArgumentTypes.NUMBER, defaultValue: 0 },
       ]},
     },
   }
diff --git a/src/interpreter/plugin/SqrtPlugin.ts b/src/interpreter/plugin/SqrtPlugin.ts
index f1b0174de2..ab3ca3b438 100644
--- a/src/interpreter/plugin/SqrtPlugin.ts
+++ b/src/interpreter/plugin/SqrtPlugin.ts
@@ -5,14 +5,14 @@
 
 import {InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 export class SqrtPlugin extends  FunctionPlugin {
   public static implementedFunctions = {
     'SQRT': {
       method: 'sqrt',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]},
     },
   }
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 4e758b5ba6..551cf1d0a1 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -5,7 +5,7 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 /**
  * Interpreter plugin containing text-specific functions
@@ -16,7 +16,7 @@ export class TextPlugin extends FunctionPlugin {
       method: 'concatenate',
       parameters: {
         list: [
-          {argumentType: 'string'}
+          {argumentType: ArgumentTypes.STRING}
         ],
         repeatedArg: true,
         expandRanges: true,
@@ -26,8 +26,8 @@ export class TextPlugin extends FunctionPlugin {
       method: 'split',
       parameters: {
         list: [
-          {argumentType: 'string'},
-          {argumentType: 'number'},
+          {argumentType: ArgumentTypes.STRING},
+          {argumentType: ArgumentTypes.NUMBER},
         ]
       },
     },
@@ -35,7 +35,7 @@ export class TextPlugin extends FunctionPlugin {
       method: 'len',
       parameters: {
         list: [
-          {argumentType: 'string'}
+          {argumentType: ArgumentTypes.STRING}
         ]
       },
     },
@@ -43,7 +43,7 @@ export class TextPlugin extends FunctionPlugin {
       method: 'trim',
       parameters: {
         list: [
-          {argumentType: 'string'}
+          {argumentType: ArgumentTypes.STRING}
         ]
       },
     },
@@ -51,7 +51,7 @@ export class TextPlugin extends FunctionPlugin {
       method: 'proper',
       parameters: {
         list: [
-          {argumentType: 'string'}
+          {argumentType: ArgumentTypes.STRING}
         ]
       },
     },
@@ -59,7 +59,7 @@ export class TextPlugin extends FunctionPlugin {
       method: 'clean',
       parameters: {
         list: [
-          {argumentType: 'string'}
+          {argumentType: ArgumentTypes.STRING}
         ]
       },
     },
@@ -67,8 +67,8 @@ export class TextPlugin extends FunctionPlugin {
       method: 'rept',
       parameters: {
         list: [
-          {argumentType: 'string'},
-          {argumentType: 'number'},
+          {argumentType: ArgumentTypes.STRING},
+          {argumentType: ArgumentTypes.NUMBER},
         ]
       },
     },
@@ -76,8 +76,8 @@ export class TextPlugin extends FunctionPlugin {
       method: 'right',
       parameters: {
         list: [
-          {argumentType: 'string'},
-          {argumentType: 'number', defaultValue: 1},
+          {argumentType: ArgumentTypes.STRING},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 1},
         ]
       },
     },
@@ -85,8 +85,8 @@ export class TextPlugin extends FunctionPlugin {
       method: 'left',
       parameters: {
         list: [
-          {argumentType: 'string'},
-          {argumentType: 'number', defaultValue: 1},
+          {argumentType: ArgumentTypes.STRING},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 1},
         ]
       },
     },
@@ -94,9 +94,9 @@ export class TextPlugin extends FunctionPlugin {
       method: 'search',
       parameters: {
         list: [
-          {argumentType: 'string'},
-          {argumentType: 'string'},
-          {argumentType: 'number', defaultValue: 1},
+          {argumentType: ArgumentTypes.STRING},
+          {argumentType: ArgumentTypes.STRING},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 1},
         ]
       },
     },
@@ -104,9 +104,9 @@ export class TextPlugin extends FunctionPlugin {
       method: 'find',
       parameters: {
         list: [
-          {argumentType: 'string'},
-          {argumentType: 'string'},
-          {argumentType: 'number', defaultValue: 1},
+          {argumentType: ArgumentTypes.STRING},
+          {argumentType: ArgumentTypes.STRING},
+          {argumentType: ArgumentTypes.NUMBER, defaultValue: 1},
         ]
       },
     }
diff --git a/src/interpreter/plugin/TrigonometryPlugin.ts b/src/interpreter/plugin/TrigonometryPlugin.ts
index e3615c4db7..dd17e22f2f 100644
--- a/src/interpreter/plugin/TrigonometryPlugin.ts
+++ b/src/interpreter/plugin/TrigonometryPlugin.ts
@@ -5,7 +5,7 @@
 
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {ProcedureAst} from '../../parser'
-import {FunctionPlugin} from './FunctionPlugin'
+import {ArgumentTypes, FunctionPlugin} from './FunctionPlugin'
 
 /**
  * Interpreter plugin containing trigonometric functions
@@ -16,50 +16,50 @@ export class TrigonometryPlugin extends FunctionPlugin {
     'ACOS': {
       method: 'acos',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]}
     },
     'ASIN': {
       method: 'asin',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]}
     },
     'COS': {
       method: 'cos',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]}
     },
     'SIN': {
       method: 'sin',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]}
     },
     'TAN': {
       method: 'tan',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]}
     },
     'ATAN': {
       method: 'atan',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]}
     },
     'ATAN2': {
       method: 'atan2',
       parameters: { list: [
-        { argumentType: 'number' },
-        { argumentType: 'number' },
+        { argumentType: ArgumentTypes.NUMBER },
+        { argumentType: ArgumentTypes.NUMBER },
       ]}
     },
     'COT': {
       method: 'ctg',
       parameters: { list: [
-        { argumentType: 'number' }
+        { argumentType: ArgumentTypes.NUMBER }
       ]}
     },
   }
diff --git a/test/optional-parameters.spec.ts b/test/optional-parameters.spec.ts
index b2d0800d15..ff4c05231d 100644
--- a/test/optional-parameters.spec.ts
+++ b/test/optional-parameters.spec.ts
@@ -1,9 +1,7 @@
 import {ErrorType, HyperFormula} from '../src'
-import {CellError, SimpleCellAddress} from '../src/Cell'
-import {coerceScalarToString} from '../src/interpreter/ArithmeticHelper'
-import {SimpleRangeValue} from '../src/interpreter/InterpreterValue'
-import {FunctionPlugin} from '../src/interpreter/plugin/FunctionPlugin'
-import {AstNodeType, ProcedureAst} from '../src/parser'
+import {SimpleCellAddress} from '../src/Cell'
+import {ArgumentTypes, FunctionPlugin} from '../src/interpreter/plugin/FunctionPlugin'
+import {ProcedureAst} from '../src/parser'
 import {adr, detailedError} from './testUtils'
 
 class FooPlugin extends FunctionPlugin {
@@ -12,8 +10,8 @@ class FooPlugin extends FunctionPlugin {
       method: 'foo',
       parameters: {
         list: [
-          { argumentType: 'string', defaultValue: 'default1'},
-          { argumentType: 'string', defaultValue: 'default2'},
+          { argumentType: ArgumentTypes.STRING, defaultValue: 'default1'},
+          { argumentType: ArgumentTypes.STRING, defaultValue: 'default2'},
         ],
       },
     },

From ac3d75847a5ae3f5cd6d837d3cbc34cca1114283 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Thu, 30 Jul 2020 23:52:42 +0200
Subject: [PATCH 87/97] docs

---
 src/interpreter/plugin/BooleanPlugin.ts     | 10 +--
 src/interpreter/plugin/CountUniquePlugin.ts |  2 +-
 src/interpreter/plugin/FunctionPlugin.ts    | 73 +++++++++++++++++++--
 src/interpreter/plugin/MedianPlugin.ts      |  2 +-
 src/interpreter/plugin/TextPlugin.ts        |  2 +-
 5 files changed, 75 insertions(+), 14 deletions(-)

diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index a78f5eb6b4..761073036e 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -37,7 +37,7 @@ export class BooleanPlugin extends FunctionPlugin {
         list: [
           {argumentType: ArgumentTypes.BOOLEAN},
         ],
-        repeatedArg: true,
+        repeatLastArg: true,
         expandRanges: true,
       },
     },
@@ -47,7 +47,7 @@ export class BooleanPlugin extends FunctionPlugin {
         list: [
           {argumentType: ArgumentTypes.BOOLEAN},
         ],
-        repeatedArg: true,
+        repeatLastArg: true,
         expandRanges: true,
       },
     },
@@ -57,7 +57,7 @@ export class BooleanPlugin extends FunctionPlugin {
         list: [
           {argumentType: ArgumentTypes.BOOLEAN},
         ],
-        repeatedArg: true,
+        repeatLastArg: true,
         expandRanges: true,
       },
     },
@@ -77,7 +77,7 @@ export class BooleanPlugin extends FunctionPlugin {
           {argumentType: ArgumentTypes.SCALAR},
           {argumentType: ArgumentTypes.SCALAR},
         ],
-        repeatedArg: true,
+        repeatLastArg: true,
       },
     },
     'IFERROR': {
@@ -105,7 +105,7 @@ export class BooleanPlugin extends FunctionPlugin {
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.SCALAR},
         ],
-        repeatedArg: true,
+        repeatLastArg: true,
       },
     },
   }
diff --git a/src/interpreter/plugin/CountUniquePlugin.ts b/src/interpreter/plugin/CountUniquePlugin.ts
index 4d469ed26b..d3c14911ce 100644
--- a/src/interpreter/plugin/CountUniquePlugin.ts
+++ b/src/interpreter/plugin/CountUniquePlugin.ts
@@ -18,7 +18,7 @@ export class CountUniquePlugin extends FunctionPlugin {
         list: [
           {argumentType: ArgumentTypes.SCALAR},
         ],
-        repeatedArg: true,
+        repeatLastArg: true,
         expandRanges: true,
       },
     },
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 737b1f995f..9d5dd2f6c0 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -34,28 +34,89 @@ export interface FunctionPluginDefinition {
 }
 
 export enum ArgumentTypes {
+
+  /**
+   * String type.
+   */
   STRING = 'STRING',
+
+  /**
+   * Floating point type.
+   */
   NUMBER = 'NUMBER',
+
+  /**
+   * Boolean type.
+   */
   BOOLEAN = 'BOOLEAN',
-  SCALAR = 'scalar',
-  NOERROR = 'noerror',
-  RANGE = 'range',
-  INTEGER = 'integer',
+
+  /**
+   * Any non-range value.
+   */
+  SCALAR = 'SCALAR',
+
+  /**
+   * Any non-range, no-error type.
+   */
+  NOERROR = 'NOERROR',
+
+  /**
+   * Range type.
+   */
+  RANGE = 'RANGE',
+
+  /**
+   * Integer type.
+   */
+  INTEGER = 'INTEGER',
 }
 
 export interface FunctionArgumentsDefinition {
   list: FunctionArgument[],
-  repeatedArg?: boolean,
+
+  /**
+   * Used for functions with variable number of arguments -- last defined argument is repeated indefinitely.
+   */
+  repeatLastArg?: boolean,
+
+  /**
+   * Ranges in arguments are inlined to (possibly multiple) scalar arguments.
+   */
   expandRanges?: boolean,
 }
 
 export interface FunctionArgument {
   argumentType: ArgumentTypes,
+
+  /**
+   * If argument is missing, its value defaults to this.
+   */
   defaultValue?: InternalScalarValue,
+
+  /**
+   * If argument is missing, and no defaultValue provided, undefined is supplied as a value, instead of throwing an error.
+   * Logically equivalent to setting defaultValue = undefined.
+   */
   optionalArg?: boolean,
+
+  /**
+   * Numeric argument needs to be greater-equal than this.
+   */
   minValue?: number,
+
+  /**
+   * Numeric argument needs to be less-equal than this.
+   */
   maxValue?: number,
+
+  /**
+   * Numeric argument needs to be less than this.
+   */
   lessThan?: number,
+
+  /**
+   * Numeric argument needs to be greater than this.
+   */
   greaterThan?: number,
 }
 
@@ -180,7 +241,7 @@ export abstract class FunctionPlugin {
     const coercedArguments: Maybe<InterpreterValue>[] = []
 
     let argCoerceFailure: Maybe<CellError> = undefined
-    if(!functionDefinition.repeatedArg && argumentDefinitions.length < scalarValues.length) {
+    if(!functionDefinition.repeatLastArg && argumentDefinitions.length < scalarValues.length) {
       return new CellError(ErrorType.NA)
     }
     for(let i=0; i<Math.max(scalarValues.length, argumentDefinitions.length); i++) {
diff --git a/src/interpreter/plugin/MedianPlugin.ts b/src/interpreter/plugin/MedianPlugin.ts
index 9c43727e5b..9d2e80583c 100644
--- a/src/interpreter/plugin/MedianPlugin.ts
+++ b/src/interpreter/plugin/MedianPlugin.ts
@@ -19,7 +19,7 @@ export class MedianPlugin extends FunctionPlugin {
         list: [
           {argumentType: ArgumentTypes.NOERROR},
         ],
-        repeatedArg: true,
+        repeatLastArg: true,
         expandRanges: true,
       },
     },
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 551cf1d0a1..6fa19c67b0 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -18,7 +18,7 @@ export class TextPlugin extends FunctionPlugin {
         list: [
           {argumentType: ArgumentTypes.STRING}
         ],
-        repeatedArg: true,
+        repeatLastArg: true,
         expandRanges: true,
       },
     },

From a6f84880a3450d54708483deb218a6534d037265 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Tue, 4 Aug 2020 13:37:00 +0200
Subject: [PATCH 88/97] flattening

---
 src/HyperFormula.ts                           |  4 +-
 src/interpreter/plugin/AbsPlugin.ts           |  6 +-
 src/interpreter/plugin/BitShiftPlugin.ts      | 12 ++--
 .../plugin/BitwiseLogicOperationsPlugin.ts    | 18 ++---
 src/interpreter/plugin/BooleanPlugin.ts       | 64 +++++++-----------
 src/interpreter/plugin/CharPlugin.ts          |  6 +-
 src/interpreter/plugin/CodePlugin.ts          |  6 +-
 src/interpreter/plugin/CountUniquePlugin.ts   |  6 +-
 src/interpreter/plugin/DatePlugin.ts          | 42 ++++--------
 src/interpreter/plugin/DegreesPlugin.ts       |  6 +-
 src/interpreter/plugin/DeltaPlugin.ts         |  6 +-
 src/interpreter/plugin/ErrorFunctionPlugin.ts | 12 ++--
 src/interpreter/plugin/ExpPlugin.ts           |  6 +-
 src/interpreter/plugin/FinancialPlugin.ts     | 24 +++----
 src/interpreter/plugin/FunctionPlugin.ts      | 34 +++++-----
 src/interpreter/plugin/InformationPlugin.ts   | 36 +++++-----
 src/interpreter/plugin/IsEvenPlugin.ts        |  6 +-
 src/interpreter/plugin/IsOddPlugin.ts         |  6 +-
 src/interpreter/plugin/LogarithmPlugin.ts     | 18 ++---
 src/interpreter/plugin/MathConstantsPlugin.ts |  8 +--
 src/interpreter/plugin/MedianPlugin.ts        |  6 +-
 src/interpreter/plugin/ModuloPlugin.ts        |  6 +-
 src/interpreter/plugin/PowerPlugin.ts         |  6 +-
 src/interpreter/plugin/RadiansPlugin.ts       |  6 +-
 .../plugin/RadixConversionPlugin.ts           | 48 +++++++-------
 src/interpreter/plugin/RandomPlugin.ts        |  4 +-
 src/interpreter/plugin/RoundingPlugin.ts      | 46 ++++++-------
 src/interpreter/plugin/SqrtPlugin.ts          |  6 +-
 src/interpreter/plugin/TextPlugin.ts          | 66 +++++++------------
 src/interpreter/plugin/TrigonometryPlugin.ts  | 48 +++++++-------
 test/interpreter/function-vlookup.spec.ts     |  4 +-
 test/optional-parameters.spec.ts              |  8 +--
 32 files changed, 244 insertions(+), 336 deletions(-)

diff --git a/src/HyperFormula.ts b/src/HyperFormula.ts
index d82295f929..802ab23487 100644
--- a/src/HyperFormula.ts
+++ b/src/HyperFormula.ts
@@ -854,7 +854,7 @@ export class HyperFormula implements TypedEmitter {
   }
 
   /**
-   * Updates the config with given new parameters.
+   * Updates the config with given new metadata.
    *
    * @param {Partial<ConfigParams>} newParams configuration options to be updated or added
    *
@@ -900,7 +900,7 @@ export class HyperFormula implements TypedEmitter {
    *
    * @example
    * ```js
-   * // should return all config parameters including default and those which were added
+   * // should return all config metadata including default and those which were added
    * const hfConfig = hfInstance.getConfig();
    * ```
    *
diff --git a/src/interpreter/plugin/AbsPlugin.ts b/src/interpreter/plugin/AbsPlugin.ts
index 527e3a3e3d..d72396768a 100644
--- a/src/interpreter/plugin/AbsPlugin.ts
+++ b/src/interpreter/plugin/AbsPlugin.ts
@@ -11,13 +11,13 @@ export class AbsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ABS': {
       method: 'abs',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]}
+      ]
     },
   }
 
   public abs(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ABS'), Math.abs)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ABS'), Math.abs)
   }
 }
diff --git a/src/interpreter/plugin/BitShiftPlugin.ts b/src/interpreter/plugin/BitShiftPlugin.ts
index 8629180b24..09e0521d8a 100644
--- a/src/interpreter/plugin/BitShiftPlugin.ts
+++ b/src/interpreter/plugin/BitShiftPlugin.ts
@@ -15,26 +15,26 @@ export class BitShiftPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'BITLSHIFT': {
       method: 'bitlshift',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
         { argumentType: ArgumentTypes.INTEGER, minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
-      ]}
+      ]
     },
     'BITRSHIFT': {
       method: 'bitrshift',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
         { argumentType: ArgumentTypes.INTEGER, minValue: SHIFT_MIN_POSITIONS, maxValue: SHIFT_MAX_POSITIONS },
-      ]}
+      ]
     },
   }
 
   public bitlshift(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BITLSHIFT'), shiftLeft)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BITLSHIFT'), shiftLeft)
   }
 
   public bitrshift(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BITRSHIFT'), shiftRight)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BITRSHIFT'), shiftRight)
   }
 }
 
diff --git a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
index 2c5ff5e654..135ba51f30 100644
--- a/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
+++ b/src/interpreter/plugin/BitwiseLogicOperationsPlugin.ts
@@ -11,41 +11,41 @@ export class BitwiseLogicOperationsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'BITAND': {
       method: 'bitand',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
         { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
-      ]}
+      ]
     },
     'BITOR': {
       method: 'bitor',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
         { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
-      ]}
+      ]
     },
     'BITXOR': {
       method: 'bitxor',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
         { argumentType: ArgumentTypes.INTEGER, minValue: 0 },
-      ]}
+      ]
     },
   }
 
   public bitand(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BITAND'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BITAND'),
       (left: number, right: number) => left & right
     )
   }
 
   public bitor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BITOR'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BITOR'),
       (left: number, right: number) => left | right
     )
   }
 
   public bitxor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BITXOR'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BITXOR'),
       (left: number, right: number) => left ^ right
     )
   }
diff --git a/src/interpreter/plugin/BooleanPlugin.ts b/src/interpreter/plugin/BooleanPlugin.ts
index 761073036e..5f870e60f9 100644
--- a/src/interpreter/plugin/BooleanPlugin.ts
+++ b/src/interpreter/plugin/BooleanPlugin.ts
@@ -15,98 +15,80 @@ export class BooleanPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'TRUE': {
       method: 'literalTrue',
-      parameters: {list: []},
+      parameters: [],
     },
     'FALSE': {
       method: 'literalFalse',
-      parameters: {list: []},
+      parameters: [],
     },
     'IF': {
       method: 'conditionalIf',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.BOOLEAN},
           {argumentType: ArgumentTypes.SCALAR},
           {argumentType: ArgumentTypes.SCALAR, defaultValue: false},
-        ]
-      },
+        ],
     },
     'AND': {
       method: 'and',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.BOOLEAN},
         ],
         repeatLastArg: true,
         expandRanges: true,
-      },
     },
     'OR': {
       method: 'or',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.BOOLEAN},
         ],
         repeatLastArg: true,
         expandRanges: true,
-      },
     },
     'XOR': {
       method: 'xor',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.BOOLEAN},
         ],
         repeatLastArg: true,
         expandRanges: true,
-      },
     },
     'NOT': {
       method: 'not',
-      parameters: {
-        list: [
+      parameters:  [
           {argumentType: ArgumentTypes.BOOLEAN},
         ]
-      },
     },
     'SWITCH': {
       method: 'switch',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NOERROR},
           {argumentType: ArgumentTypes.SCALAR},
           {argumentType: ArgumentTypes.SCALAR},
         ],
         repeatLastArg: true,
-      },
     },
     'IFERROR': {
       method: 'iferror',
-      parameters: {
-        list: [
+      parameters:  [
           {argumentType: ArgumentTypes.SCALAR},
           {argumentType: ArgumentTypes.SCALAR},
         ]
-      },
     },
     'IFNA': {
       method: 'ifna',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.SCALAR},
           {argumentType: ArgumentTypes.SCALAR},
         ]
-      },
     },
     'CHOOSE': {
       method: 'choose',
-      parameters: {
-        list: [
+      parameters:  [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.SCALAR},
         ],
         repeatLastArg: true,
-      },
     },
   }
 
@@ -119,7 +101,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public literalTrue(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('TRUE'), () => true)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('TRUE'), () => true)
   }
 
   /**
@@ -131,7 +113,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public literalFalse(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('FALSE'), () => false)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('FALSE'), () => false)
   }
 
   /**
@@ -143,7 +125,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public conditionalIf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InterpreterValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('IF'), (condition, arg2, arg3) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('IF'), (condition, arg2, arg3) => {
       return condition ? arg2 : arg3
     })
   }
@@ -157,7 +139,7 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public and(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('AND'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('AND'),
       (...args) => !args.some((arg: boolean) => !arg)
     )
   }
@@ -171,17 +153,17 @@ export class BooleanPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public or(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('OR'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('OR'),
       (...args) => args.some((arg: boolean) => arg)
     )
   }
 
   public not(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('NOT'), (arg) => !arg)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('NOT'), (arg) => !arg)
   }
 
   public xor(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('XOR'), (...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('XOR'), (...args) => {
       let cnt = 0
       args.forEach((arg: boolean) => {
         if (arg) {
@@ -193,7 +175,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public switch(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('SWITCH'), (selector, ...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('SWITCH'), (selector, ...args) => {
       const n = args.length
       let i = 0
       for (; i + 1 < n; i += 2) {
@@ -213,7 +195,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public iferror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('IFERROR'), (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('IFERROR'), (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
       if (arg1 instanceof CellError) {
         return arg2
       } else {
@@ -223,7 +205,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public ifna(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('IFNA'), (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('IFNA'), (arg1: InternalScalarValue, arg2: InternalScalarValue) => {
       if (arg1 instanceof CellError && arg1.type === ErrorType.NA) {
         return arg2
       } else {
@@ -233,7 +215,7 @@ export class BooleanPlugin extends FunctionPlugin {
   }
 
   public choose(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('CHOOSE'), (selector, ...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('CHOOSE'), (selector, ...args) => {
       if (selector !== Math.round(selector) || selector < 1 || selector > args.length) {
         return new CellError(ErrorType.NUM)
       }
diff --git a/src/interpreter/plugin/CharPlugin.ts b/src/interpreter/plugin/CharPlugin.ts
index ddf44af14e..684ccaab39 100644
--- a/src/interpreter/plugin/CharPlugin.ts
+++ b/src/interpreter/plugin/CharPlugin.ts
@@ -11,16 +11,14 @@ export class CharPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CHAR': {
       method: 'char',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER}
         ],
-      }
     },
   }
 
   public char(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('CHAR'), (value: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('CHAR'), (value: number) => {
       if (value < 1 || value > 255) {
         return new CellError(ErrorType.NUM)
       }
diff --git a/src/interpreter/plugin/CodePlugin.ts b/src/interpreter/plugin/CodePlugin.ts
index 3c39809f06..92aee59af4 100644
--- a/src/interpreter/plugin/CodePlugin.ts
+++ b/src/interpreter/plugin/CodePlugin.ts
@@ -11,16 +11,14 @@ export class CodePlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CODE': {
       method: 'code',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING}
         ]
-      },
     },
   }
 
   public code(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('CODE'), (value: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('CODE'), (value: string) => {
       if (value.length === 0) {
         return new CellError(ErrorType.VALUE)
       }
diff --git a/src/interpreter/plugin/CountUniquePlugin.ts b/src/interpreter/plugin/CountUniquePlugin.ts
index d3c14911ce..c308a6319d 100644
--- a/src/interpreter/plugin/CountUniquePlugin.ts
+++ b/src/interpreter/plugin/CountUniquePlugin.ts
@@ -14,13 +14,11 @@ export class CountUniquePlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'COUNTUNIQUE': {
       method: 'countunique',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.SCALAR},
         ],
         repeatLastArg: true,
         expandRanges: true,
-      },
     },
   }
 
@@ -33,7 +31,7 @@ export class CountUniquePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public countunique(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('COUNTUNIQUE'), (...args: InternalScalarValue[]) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('COUNTUNIQUE'), (...args: InternalScalarValue[]) => {
       const valuesSet = new Set<number | string | boolean | EmptyValueType>()
       const errorsSet = new Set<ErrorType>()
 
diff --git a/src/interpreter/plugin/DatePlugin.ts b/src/interpreter/plugin/DatePlugin.ts
index 6db1939e3d..b10353cb33 100644
--- a/src/interpreter/plugin/DatePlugin.ts
+++ b/src/interpreter/plugin/DatePlugin.ts
@@ -17,64 +17,50 @@ export class DatePlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DATE': {
       method: 'date',
-      parameters: {
-        list: [
+      parameters:  [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
         ]
-      },
     },
     'MONTH': {
       method: 'month',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
         ]
-      },
     },
     'YEAR': {
       method: 'year',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
         ]
-      },
     },
     'TEXT': {
       method: 'text',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.STRING},
         ]
-      },
     },
     'EOMONTH': {
       method: 'eomonth',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
         ]
-      },
     },
     'DAY': {
       method: 'day',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
         ]
-      },
     },
     'DAYS': {
       method: 'days',
-      parameters: {
-        list: [
+      parameters:[
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
         ]
-      },
     },
   }
 
@@ -87,7 +73,7 @@ export class DatePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public date(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DATE'), (year, month, day) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DATE'), (year, month, day) => {
       const d = Math.trunc(day)
       let m = Math.trunc(month)
       let y = Math.trunc(year)
@@ -110,20 +96,20 @@ export class DatePlugin extends FunctionPlugin {
   }
 
   public eomonth(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('EOMONTH'), (dateNumber, numberOfMonthsToShift) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('EOMONTH'), (dateNumber, numberOfMonthsToShift) => {
       const date = this.interpreter.dateHelper.numberToSimpleDate(dateNumber)
       return this.interpreter.dateHelper.dateToNumber(endOfMonth(offsetMonth(date, numberOfMonthsToShift)))
     })
   }
 
   public day(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DAY'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DAY'),
       (dateNumber) => this.interpreter.dateHelper.numberToSimpleDate(dateNumber).day
     )
   }
 
   public days(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DAYS'), (endDate, startDate) => endDate - startDate)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DAYS'), (endDate, startDate) => endDate - startDate)
   }
 
   /**
@@ -135,7 +121,7 @@ export class DatePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public month(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('MONTH'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('MONTH'),
       (dateNumber) => this.interpreter.dateHelper.numberToSimpleDate(dateNumber).month
     )
   }
@@ -149,7 +135,7 @@ export class DatePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public year(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('YEAR'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('YEAR'),
       (dateNumber) => this.interpreter.dateHelper.numberToSimpleDate(dateNumber).year
     )
   }
@@ -163,7 +149,7 @@ export class DatePlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public text(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('TEXT'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('TEXT'),
       (numberRepresentation, formatArg) =>format(numberRepresentation, formatArg, this.config, this.interpreter.dateHelper)
     )
   }
diff --git a/src/interpreter/plugin/DegreesPlugin.ts b/src/interpreter/plugin/DegreesPlugin.ts
index b1e428b366..de0a7e506c 100644
--- a/src/interpreter/plugin/DegreesPlugin.ts
+++ b/src/interpreter/plugin/DegreesPlugin.ts
@@ -11,16 +11,14 @@ export class DegreesPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DEGREES': {
       method: 'degrees',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER}
         ]
-      },
     },
   }
 
   public degrees(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DEGREES'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DEGREES'),
       (arg) => arg * (180 / Math.PI)
     )
   }
diff --git a/src/interpreter/plugin/DeltaPlugin.ts b/src/interpreter/plugin/DeltaPlugin.ts
index 96bd936da0..97aac059b8 100644
--- a/src/interpreter/plugin/DeltaPlugin.ts
+++ b/src/interpreter/plugin/DeltaPlugin.ts
@@ -11,17 +11,15 @@ export class DeltaPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DELTA': {
       method: 'delta',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
-      },
     },
   }
 
   public delta(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DELTA'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DELTA'),
       (left: number, right: number) => (left === right ? 1 : 0)
     )
   }
diff --git a/src/interpreter/plugin/ErrorFunctionPlugin.ts b/src/interpreter/plugin/ErrorFunctionPlugin.ts
index f4cfa362f1..bba1b9528c 100644
--- a/src/interpreter/plugin/ErrorFunctionPlugin.ts
+++ b/src/interpreter/plugin/ErrorFunctionPlugin.ts
@@ -11,25 +11,21 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ERF': {
       method: 'erf',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER, optionalArg: true},
         ]
-      },
     },
     'ERFC': {
       method: 'erfc',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER}
         ]
-      },
     },
   }
 
   public erf(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ERF'), (lowerBound, upperBound) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ERF'), (lowerBound, upperBound) => {
       if (upperBound === undefined) {
         return erf(lowerBound)
       } else {
@@ -39,7 +35,7 @@ export class ErrorFunctionPlugin extends FunctionPlugin {
   }
 
   public erfc(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ERFC'), erfc)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ERFC'), erfc)
   }
 }
 
diff --git a/src/interpreter/plugin/ExpPlugin.ts b/src/interpreter/plugin/ExpPlugin.ts
index cfe3a97e9a..c96b3eb856 100644
--- a/src/interpreter/plugin/ExpPlugin.ts
+++ b/src/interpreter/plugin/ExpPlugin.ts
@@ -11,9 +11,9 @@ export class ExpPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'EXP': {
       method: 'exp',
-      parameters: { list: [
+      parameters:[
         { argumentType: ArgumentTypes.NUMBER }
-      ]},
+      ],
     },
   }
 
@@ -26,6 +26,6 @@ export class ExpPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public exp(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('EXP'), Math.exp)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('EXP'), Math.exp)
   }
 }
diff --git a/src/interpreter/plugin/FinancialPlugin.ts b/src/interpreter/plugin/FinancialPlugin.ts
index c3e033e554..b72cb343a3 100644
--- a/src/interpreter/plugin/FinancialPlugin.ts
+++ b/src/interpreter/plugin/FinancialPlugin.ts
@@ -11,20 +11,17 @@ export class FinancialPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'PMT': {
       method: 'pmt',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
-      },
     },
     'IPMT': {
       method: 'ipmt',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
@@ -32,12 +29,10 @@ export class FinancialPlugin extends FunctionPlugin {
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
-      },
     },
     'PPMT': {
       method: 'ppmt',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
@@ -45,36 +40,33 @@ export class FinancialPlugin extends FunctionPlugin {
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
-      },
     },
     'FV': {
       method: 'fv',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
         ]
-      },
     },
   }
 
   public pmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('PMT'), pmtCore)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('PMT'), pmtCore)
   }
 
   public ipmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('IPMT'), ipmtCore)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('IPMT'), ipmtCore)
   }
 
   public ppmt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('PPMT'), ppmtCore)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('PPMT'), ppmtCore)
   }
 
   public fv(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('FV'), fvCore)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('FV'), fvCore)
   }
 }
 
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index 9d5dd2f6c0..612aa8c4ba 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -21,10 +21,20 @@ export interface ImplementedFunctions {
 
 export interface FunctionMetadata {
   method: string,
-  parameters?: FunctionArgumentsDefinition,
+  parameters?: FunctionArgument[],
   isVolatile?: boolean,
   isDependentOnSheetStructureChange?: boolean,
   doesNotNeedArgumentsToBeComputed?: boolean,
+
+  /**
+   * Used for functions with variable number of arguments -- last defined argument is repeated indefinitely.
+   */
+  repeatLastArg?: boolean,
+
+  /**
+   * Ranges in arguments are inlined to (possibly multiple) scalar arguments.
+   */
+  expandRanges?: boolean,
 }
 
 export interface FunctionPluginDefinition {
@@ -71,20 +81,6 @@ export enum ArgumentTypes {
   INTEGER = 'INTEGER',
 }
 
-export interface FunctionArgumentsDefinition {
-  list: FunctionArgument[],
-
-  /**
-   * Used for functions with variable number of arguments -- last defined argument is repeated indefinitely.
-   */
-  repeatLastArg?: boolean,
-
-  /**
-   * Ranges in arguments are inlined to (possibly multiple) scalar arguments.
-   */
-  expandRanges?: boolean,
-}
-
 export interface FunctionArgument {
   argumentType: ArgumentTypes,
 
@@ -226,10 +222,10 @@ export abstract class FunctionPlugin {
   protected runFunction = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
-    functionDefinition: FunctionArgumentsDefinition,
+    functionDefinition: FunctionMetadata,
     fn: (...arg: any) => InternalScalarValue
   ) => {
-    const argumentDefinitions: FunctionArgument[] = functionDefinition.list
+    const argumentDefinitions: FunctionArgument[] = functionDefinition.parameters!
     let scalarValues: [InterpreterValue, boolean][]
 
     if(functionDefinition.expandRanges) {
@@ -276,8 +272,8 @@ export abstract class FunctionPlugin {
     return argCoerceFailure ?? fn(...coercedArguments)
   }
 
-  protected parameters(name: string): FunctionArgumentsDefinition {
-    const params = (this.constructor as FunctionPluginDefinition).implementedFunctions[name]?.parameters
+  protected metadata(name: string): FunctionMetadata {
+    const params = (this.constructor as FunctionPluginDefinition).implementedFunctions[name]
     if (params !== undefined) {
       return params
     }
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index b4deaa3f9b..30ea9e1b10 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -16,39 +16,39 @@ export class InformationPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISERROR': {
       method: 'iserror',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.SCALAR}
-      ]}
+      ]
     },
     'ISBLANK': {
       method: 'isblank',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.SCALAR}
-      ]}
+      ]
     },
     'ISNUMBER': {
       method: 'isnumber',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.SCALAR}
-      ]}
+      ]
     },
     'ISLOGICAL': {
       method: 'islogical',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.SCALAR}
-      ]}
+      ]
     },
     'ISTEXT': {
       method: 'istext',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.SCALAR}
-      ]}
+      ]
     },
     'ISNONTEXT': {
       method: 'isnontext',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.SCALAR}
-      ]}
+      ]
     },
     'COLUMNS': {
       method: 'columns',
@@ -74,7 +74,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public iserror(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ISERROR'), (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ISERROR'), (arg: InternalScalarValue) =>
       (arg instanceof CellError)
     )
   }
@@ -88,7 +88,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isblank(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ISBLANK'), (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ISBLANK'), (arg: InternalScalarValue) =>
       (arg === EmptyValue)
     )
   }
@@ -102,7 +102,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isnumber(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ISNUMBER'), (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ISNUMBER'), (arg: InternalScalarValue) =>
       (typeof arg === 'number')
     )
   }
@@ -116,7 +116,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public islogical(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ISLOGICAL'), (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ISLOGICAL'), (arg: InternalScalarValue) =>
       (typeof arg === 'boolean')
     )
   }
@@ -130,7 +130,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public istext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ISTEXT'), (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ISTEXT'), (arg: InternalScalarValue) =>
       (typeof arg === 'string')
     )
   }
@@ -144,7 +144,7 @@ export class InformationPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public isnontext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ISNONTEXT'), (arg: InternalScalarValue) =>
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ISNONTEXT'), (arg: InternalScalarValue) =>
       (typeof arg !== 'string')
     )
   }
diff --git a/src/interpreter/plugin/IsEvenPlugin.ts b/src/interpreter/plugin/IsEvenPlugin.ts
index 67a3432d49..720d3f6bf5 100644
--- a/src/interpreter/plugin/IsEvenPlugin.ts
+++ b/src/interpreter/plugin/IsEvenPlugin.ts
@@ -11,14 +11,14 @@ export class IsEvenPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISEVEN': {
       method: 'iseven',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER}
-      ]}
+      ]
     },
   }
 
   public iseven(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ISEVEN'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ISEVEN'),
       (val) => (val % 2 === 0)
     )
   }
diff --git a/src/interpreter/plugin/IsOddPlugin.ts b/src/interpreter/plugin/IsOddPlugin.ts
index 3e307575b3..512e24649f 100644
--- a/src/interpreter/plugin/IsOddPlugin.ts
+++ b/src/interpreter/plugin/IsOddPlugin.ts
@@ -11,16 +11,14 @@ export class IsOddPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ISODD': {
       method: 'isodd',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER}
         ]
-      }
     },
   }
 
   public isodd(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ISODD'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ISODD'),
       (val) => (val % 2 === 1)
     )
   }
diff --git a/src/interpreter/plugin/LogarithmPlugin.ts b/src/interpreter/plugin/LogarithmPlugin.ts
index 8346b4a22d..88174492fc 100644
--- a/src/interpreter/plugin/LogarithmPlugin.ts
+++ b/src/interpreter/plugin/LogarithmPlugin.ts
@@ -12,42 +12,36 @@ export class LogarithmPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'LOG10': {
       method: 'log10',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER}
         ]
-      },
     },
     'LOG': {
       method: 'log',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER, greaterThan: 0},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 10, greaterThan: 0},
         ]
-      },
     },
     'LN': {
       method: 'ln',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NUMBER}
         ]
-      },
     },
   }
 
   public log10(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('LOG10'), Math.log10)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('LOG10'), Math.log10)
   }
 
   public log(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('LOG'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('LOG'),
       (arg: number, base: number) => Math.log(arg) / Math.log(base)
     )
   }
 
   public ln(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('LN'), Math.log)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('LN'), Math.log)
   }
 }
diff --git a/src/interpreter/plugin/MathConstantsPlugin.ts b/src/interpreter/plugin/MathConstantsPlugin.ts
index 174e2f8571..b3cd67e41a 100644
--- a/src/interpreter/plugin/MathConstantsPlugin.ts
+++ b/src/interpreter/plugin/MathConstantsPlugin.ts
@@ -14,22 +14,22 @@ export class MathConstantsPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'PI': {
       method: 'pi',
-      parameters: {list: []},
+      parameters: [],
     },
     'E': {
       method: 'e',
-      parameters: {list: []},
+      parameters: [],
     },
   }
 
   public pi(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('PI'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('PI'),
       () => PI
     )
   }
 
   public e(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('E'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('E'),
       () => E
     )
   }
diff --git a/src/interpreter/plugin/MedianPlugin.ts b/src/interpreter/plugin/MedianPlugin.ts
index 9d2e80583c..c56315242e 100644
--- a/src/interpreter/plugin/MedianPlugin.ts
+++ b/src/interpreter/plugin/MedianPlugin.ts
@@ -15,13 +15,11 @@ export class MedianPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'MEDIAN': {
       method: 'median',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.NOERROR},
         ],
         repeatLastArg: true,
         expandRanges: true,
-      },
     },
   }
 
@@ -34,7 +32,7 @@ export class MedianPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public median(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('MEDIAN'), (...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('MEDIAN'), (...args) => {
       const values: number[] = args.filter((val: InternalScalarValue) => (typeof val === 'number'))
       if (values.length === 0) {
         return new CellError(ErrorType.NUM)
diff --git a/src/interpreter/plugin/ModuloPlugin.ts b/src/interpreter/plugin/ModuloPlugin.ts
index e91a1ebc69..158a7bf424 100644
--- a/src/interpreter/plugin/ModuloPlugin.ts
+++ b/src/interpreter/plugin/ModuloPlugin.ts
@@ -11,15 +11,15 @@ export class ModuloPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'MOD': {
       method: 'mod',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER },
         { argumentType: ArgumentTypes.NUMBER },
-      ]},
+      ],
     },
   }
 
   public mod(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('MOD'), (dividend: number, divisor: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('MOD'), (dividend: number, divisor: number) => {
       if (divisor === 0) {
         return new CellError(ErrorType.DIV_BY_ZERO)
       } else {
diff --git a/src/interpreter/plugin/PowerPlugin.ts b/src/interpreter/plugin/PowerPlugin.ts
index 6d5b4cf5a9..f3fe66a717 100644
--- a/src/interpreter/plugin/PowerPlugin.ts
+++ b/src/interpreter/plugin/PowerPlugin.ts
@@ -11,14 +11,14 @@ export class PowerPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'POWER': {
       method: 'power',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER },
         { argumentType: ArgumentTypes.NUMBER },
-      ]},
+      ],
     },
   }
 
   public power(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('POWER'), Math.pow)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('POWER'), Math.pow)
   }
 }
diff --git a/src/interpreter/plugin/RadiansPlugin.ts b/src/interpreter/plugin/RadiansPlugin.ts
index ed12a09c84..4588dfdd90 100644
--- a/src/interpreter/plugin/RadiansPlugin.ts
+++ b/src/interpreter/plugin/RadiansPlugin.ts
@@ -11,14 +11,14 @@ export class RadiansPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'RADIANS': {
       method: 'radians',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]},
+      ],
     },
   }
 
   public radians(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('RADIANS'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('RADIANS'),
       (arg) => arg * (Math.PI / 180)
     )
   }
diff --git a/src/interpreter/plugin/RadixConversionPlugin.ts b/src/interpreter/plugin/RadixConversionPlugin.ts
index ea6b9891b1..3a3046182d 100644
--- a/src/interpreter/plugin/RadixConversionPlugin.ts
+++ b/src/interpreter/plugin/RadixConversionPlugin.ts
@@ -19,82 +19,82 @@ export class RadixConversionPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'DEC2BIN': {
       method: 'dec2bin',
-      parameters: { list: [
+      parameters:  [
         { argumentType: ArgumentTypes.NUMBER, minValue: minValFromBase(2), maxValue: maxValFromBase(2) },
         { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 1, maxValue: 10 },
-      ]},
+      ],
     },
     'DEC2OCT': {
       method: 'dec2oct',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER, minValue: minValFromBase(8), maxValue: maxValFromBase(8) },
         { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 1, maxValue: 10 },
-      ]},
+      ],
     },
     'DEC2HEX': {
       method: 'dec2hex',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER, minValue: minValFromBase(16), maxValue: maxValFromBase(16) },
         { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 1, maxValue: 10 },
-      ]},
+      ],
     },
     'BIN2DEC': {
       method: 'bin2dec',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.STRING }
-      ]},
+      ],
     },
     'BIN2OCT': {
       method: 'bin2oct',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.STRING },
         { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
-      ]},
+      ],
     },
     'BIN2HEX': {
       method: 'bin2hex',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.STRING },
         { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
-      ]},
+      ],
     },
     'DECIMAL': {
       method: 'decimal',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.STRING },
         { argumentType: ArgumentTypes.NUMBER, minValue: MIN_BASE, maxValue: MAX_BASE },
-      ]},
+      ],
     },
     'BASE': {
       method: 'base',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER, minValue: 0 },
         { argumentType: ArgumentTypes.NUMBER, minValue: MIN_BASE, maxValue: MAX_BASE },
         { argumentType: ArgumentTypes.NUMBER, optionalArg: true, minValue: 0, maxValue: DECIMAL_NUMBER_OF_BITS},
-      ]},
+      ],
     },
   }
 
   public dec2bin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DEC2BIN'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DEC2BIN'),
       (value, places) => decimalToBaseWithExactPadding(value, 2, places)
     )
   }
 
   public dec2oct(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DEC2OCT'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DEC2OCT'),
       (value, places) => decimalToBaseWithExactPadding(value, 8, places)
     )
   }
 
   public dec2hex(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DEC2HEX'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DEC2HEX'),
       (value, places) => decimalToBaseWithExactPadding(value, 16, places)
     )
   }
 
   public bin2dec(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BIN2DEC'), (binary) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BIN2DEC'), (binary) => {
         const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
         if(binaryWithSign === undefined) {
           return new CellError(ErrorType.NUM)
@@ -104,7 +104,7 @@ export class RadixConversionPlugin extends FunctionPlugin {
   }
 
   public bin2oct(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BIN2OCT'), (binary, places) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BIN2OCT'), (binary, places) => {
       const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
       if(binaryWithSign === undefined) {
         return new CellError(ErrorType.NUM)
@@ -114,7 +114,7 @@ export class RadixConversionPlugin extends FunctionPlugin {
   }
 
   public bin2hex(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BIN2HEX'), (binary, places) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BIN2HEX'), (binary, places) => {
       const binaryWithSign = coerceStringToBase(binary, 2, NUMBER_OF_BITS)
       if(binaryWithSign === undefined) {
         return new CellError(ErrorType.NUM)
@@ -124,11 +124,11 @@ export class RadixConversionPlugin extends FunctionPlugin {
   }
 
   public base(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('BASE'), decimalToBaseWithMinimumPadding)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('BASE'), decimalToBaseWithMinimumPadding)
   }
 
   public decimal(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('DECIMAL'), (arg, base) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('DECIMAL'), (arg, base) => {
       const input = coerceStringToBase(arg, base, DECIMAL_NUMBER_OF_BITS)
       if(input === undefined) {
         return new CellError(ErrorType.NUM)
diff --git a/src/interpreter/plugin/RandomPlugin.ts b/src/interpreter/plugin/RandomPlugin.ts
index 8fa32c1333..4ec0c08650 100644
--- a/src/interpreter/plugin/RandomPlugin.ts
+++ b/src/interpreter/plugin/RandomPlugin.ts
@@ -11,7 +11,7 @@ export class RandomPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'RAND': {
       method: 'rand',
-      parameters: { list: [] },
+      parameters: [],
       isVolatile: true,
     },
   }
@@ -26,6 +26,6 @@ export class RandomPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public rand(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('RAND'), Math.random)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('RAND'), Math.random)
   }
 }
diff --git a/src/interpreter/plugin/RoundingPlugin.ts b/src/interpreter/plugin/RoundingPlugin.ts
index d60e040538..261b7936a2 100644
--- a/src/interpreter/plugin/RoundingPlugin.ts
+++ b/src/interpreter/plugin/RoundingPlugin.ts
@@ -21,62 +21,62 @@ export class RoundingPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ROUNDUP': {
       method: 'roundup',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER },
         { argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
-      ]},
+      ],
     },
     'ROUNDDOWN': {
       method: 'rounddown',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER },
         { argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
-      ]},
+      ],
     },
     'ROUND': {
       method: 'round',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER },
         { argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
-      ]},
+      ],
     },
     'TRUNC': {
       method: 'trunc',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER },
         { argumentType: ArgumentTypes.NUMBER, defaultValue: 0},
-      ]},
+      ],
     },
     'INT': {
       method: 'intFunc',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]},
+      ],
     },
     'EVEN': {
       method: 'even',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]},
+      ],
     },
     'ODD': {
       method: 'odd',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]},
+      ],
     },
     'CEILING': {
       method: 'ceiling',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER },
         { argumentType: ArgumentTypes.NUMBER, defaultValue: 1 },
         { argumentType: ArgumentTypes.NUMBER, defaultValue: 0 },
-      ]},
+      ],
     },
   }
 
   public roundup(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ROUNDDOWN'), (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ROUNDDOWN'), (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.ceil(-numberToRound * placesMultiplier) / placesMultiplier
@@ -87,7 +87,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public rounddown(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ROUNDDOWN'), (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ROUNDDOWN'), (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.floor(-numberToRound * placesMultiplier) / placesMultiplier
@@ -98,7 +98,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public round(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ROUND'), (numberToRound: number, places: number): number => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ROUND'), (numberToRound: number, places: number): number => {
       const placesMultiplier = Math.pow(10, places)
       if (numberToRound < 0) {
         return -Math.round(-numberToRound * placesMultiplier) / placesMultiplier
@@ -113,7 +113,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public intFunc(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('INT'), (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('INT'), (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -Math.floor(-coercedNumberToRound)
       } else {
@@ -123,7 +123,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public even(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('EVEN'), (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('EVEN'), (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -findNextEvenNumber(-coercedNumberToRound)
       } else {
@@ -133,7 +133,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public odd(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ODD'), (coercedNumberToRound) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ODD'), (coercedNumberToRound) => {
       if (coercedNumberToRound < 0) {
         return -findNextOddNumber(-coercedNumberToRound)
       } else {
@@ -143,7 +143,7 @@ export class RoundingPlugin extends FunctionPlugin {
   }
 
   public ceiling(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('CEILING'), (value: number, significance: number, mode: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('CEILING'), (value: number, significance: number, mode: number) => {
       if (significance === 0 || value === 0) {
         return 0
       }
diff --git a/src/interpreter/plugin/SqrtPlugin.ts b/src/interpreter/plugin/SqrtPlugin.ts
index ab3ca3b438..7694aa0d1f 100644
--- a/src/interpreter/plugin/SqrtPlugin.ts
+++ b/src/interpreter/plugin/SqrtPlugin.ts
@@ -11,13 +11,13 @@ export class SqrtPlugin extends  FunctionPlugin {
   public static implementedFunctions = {
     'SQRT': {
       method: 'sqrt',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]},
+      ],
     },
   }
 
   public sqrt(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('SQRT'), Math.sqrt)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('SQRT'), Math.sqrt)
   }
 }
diff --git a/src/interpreter/plugin/TextPlugin.ts b/src/interpreter/plugin/TextPlugin.ts
index 6fa19c67b0..1386fa4283 100644
--- a/src/interpreter/plugin/TextPlugin.ts
+++ b/src/interpreter/plugin/TextPlugin.ts
@@ -14,101 +14,79 @@ export class TextPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'CONCATENATE': {
       method: 'concatenate',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING}
         ],
         repeatLastArg: true,
         expandRanges: true,
-      },
     },
     'SPLIT': {
       method: 'split',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING},
           {argumentType: ArgumentTypes.NUMBER},
         ]
-      },
     },
     'LEN': {
       method: 'len',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING}
         ]
-      },
     },
     'TRIM': {
       method: 'trim',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING}
         ]
-      },
     },
     'PROPER': {
       method: 'proper',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING}
         ]
-      },
     },
     'CLEAN': {
       method: 'clean',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING}
         ]
-      },
     },
     'REPT': {
       method: 'rept',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING},
           {argumentType: ArgumentTypes.NUMBER},
         ]
-      },
     },
     'RIGHT': {
       method: 'right',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 1},
         ]
-      },
     },
     'LEFT': {
       method: 'left',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 1},
         ]
-      },
     },
     'SEARCH': {
       method: 'search',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING},
           {argumentType: ArgumentTypes.STRING},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 1},
         ]
-      },
     },
     'FIND': {
       method: 'find',
-      parameters: {
-        list: [
+      parameters: [
           {argumentType: ArgumentTypes.STRING},
           {argumentType: ArgumentTypes.STRING},
           {argumentType: ArgumentTypes.NUMBER, defaultValue: 1},
         ]
-      },
     }
   }
 
@@ -121,7 +99,7 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public concatenate(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('CONCATENATE'), (...args) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('CONCATENATE'), (...args) => {
       return ''.concat(...args)
     })
   }
@@ -135,7 +113,7 @@ export class TextPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public split(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('SPLIT'), (stringToSplit: string, indexToUse: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('SPLIT'), (stringToSplit: string, indexToUse: number) => {
       const splittedString = stringToSplit.split(' ')
 
       if (indexToUse >= splittedString.length || indexToUse < 0) {
@@ -147,32 +125,32 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public len(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('LEN'), (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('LEN'), (arg: string) => {
       return arg.length
     })
   }
 
   public trim(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('TRIM'), (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('TRIM'), (arg: string) => {
       return arg.replace(/^ +| +$/g, '').replace(/ +/g, ' ')
     })
   }
 
   public proper(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('PROPER'), (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('PROPER'), (arg: string) => {
       return arg.replace(/\w\S*/g, word => word.charAt(0).toUpperCase() + word.substr(1).toLowerCase())
     })
   }
 
   public clean(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('CLEAN'), (arg: string) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('CLEAN'), (arg: string) => {
       // eslint-disable-next-line no-control-regex
       return arg.replace(/[\u0000-\u001F]/g, '')
     })
   }
 
   public rept(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('REPT'), (text: string, count: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('REPT'), (text: string, count: number) => {
       if (count < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -181,7 +159,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public right(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('RIGHT'), (text: string, length: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('RIGHT'), (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       } else if (length === 0) {
@@ -192,7 +170,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public left(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('LEFT'), (text: string, length: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('LEFT'), (text: string, length: number) => {
       if (length < 0) {
         return new CellError(ErrorType.VALUE)
       }
@@ -201,7 +179,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public search(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('SEARCH'), (pattern, text: string, startIndex: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('SEARCH'), (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }
@@ -221,7 +199,7 @@ export class TextPlugin extends FunctionPlugin {
   }
 
   public find(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('FIND'), (pattern, text: string, startIndex: number) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('FIND'), (pattern, text: string, startIndex: number) => {
       if (startIndex < 1 || startIndex > text.length) {
         return new CellError(ErrorType.VALUE)
       }
diff --git a/src/interpreter/plugin/TrigonometryPlugin.ts b/src/interpreter/plugin/TrigonometryPlugin.ts
index dd17e22f2f..d852c661d9 100644
--- a/src/interpreter/plugin/TrigonometryPlugin.ts
+++ b/src/interpreter/plugin/TrigonometryPlugin.ts
@@ -15,52 +15,52 @@ export class TrigonometryPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'ACOS': {
       method: 'acos',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]}
+      ]
     },
     'ASIN': {
       method: 'asin',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]}
+      ]
     },
     'COS': {
       method: 'cos',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]}
+      ]
     },
     'SIN': {
       method: 'sin',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]}
+      ]
     },
     'TAN': {
       method: 'tan',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]}
+      ]
     },
     'ATAN': {
       method: 'atan',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]}
+      ]
     },
     'ATAN2': {
       method: 'atan2',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER },
         { argumentType: ArgumentTypes.NUMBER },
-      ]}
+      ]
     },
     'COT': {
       method: 'ctg',
-      parameters: { list: [
+      parameters: [
         { argumentType: ArgumentTypes.NUMBER }
-      ]}
+      ]
     },
   }
 
@@ -73,35 +73,35 @@ export class TrigonometryPlugin extends FunctionPlugin {
    * @param formulaAddress
    */
   public acos(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ACOS'), Math.acos)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ACOS'), Math.acos)
   }
 
   public asin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ASIN'), Math.asin)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ASIN'), Math.asin)
   }
 
   public cos(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('COS'), Math.cos)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('COS'), Math.cos)
   }
 
   public sin(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('SIN'), Math.sin)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('SIN'), Math.sin)
   }
 
   public tan(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('TAN'), Math.tan)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('TAN'), Math.tan)
   }
 
   public atan(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ATAN'), Math.atan)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ATAN'), Math.atan)
   }
 
   public atan2(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('ATAN2'), Math.atan2)
+    return this.runFunction(ast.args, formulaAddress, this.metadata('ATAN2'), Math.atan2)
   }
 
   public ctg(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('COT'), (coercedArg) => {
+    return this.runFunction(ast.args, formulaAddress, this.metadata('COT'), (coercedArg) => {
       if (coercedArg === 0) {
         return new CellError(ErrorType.DIV_BY_ZERO)
       } else {
diff --git a/test/interpreter/function-vlookup.spec.ts b/test/interpreter/function-vlookup.spec.ts
index 368c304b01..1debbfe2ca 100644
--- a/test/interpreter/function-vlookup.spec.ts
+++ b/test/interpreter/function-vlookup.spec.ts
@@ -6,7 +6,7 @@ import {Sheet} from '../../src/Sheet'
 
 const sharedExamples = (builder: (sheet: Sheet, config?: Partial<ConfigParams>) => HyperFormula) => {
   describe('VLOOKUP - args validation', () => {
-    it('not enough parameters', () => {
+    it('not enough metadata', () => {
       const engine = builder([
         ['=VLOOKUP(1, A2:B3)'],
       ])
@@ -14,7 +14,7 @@ const sharedExamples = (builder: (sheet: Sheet, config?: Partial<ConfigParams>)
       expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
     })
 
-    it('too many parameters', () => {
+    it('too many metadata', () => {
       const engine = builder([
         ['=VLOOKUP(1, A2:B3, 2, TRUE(), "foo")'],
       ])
diff --git a/test/optional-parameters.spec.ts b/test/optional-parameters.spec.ts
index ff4c05231d..4f61452cac 100644
--- a/test/optional-parameters.spec.ts
+++ b/test/optional-parameters.spec.ts
@@ -8,23 +8,21 @@ class FooPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'FOO': {
       method: 'foo',
-      parameters: {
-        list: [
+      parameters: [
           { argumentType: ArgumentTypes.STRING, defaultValue: 'default1'},
           { argumentType: ArgumentTypes.STRING, defaultValue: 'default2'},
         ],
-      },
     },
   }
 
   public foo(ast: ProcedureAst, formulaAddress: SimpleCellAddress) {
-    return this.runFunction(ast.args, formulaAddress, this.parameters('FOO'),
+    return this.runFunction(ast.args, formulaAddress, this.metadata('FOO'),
       (arg1, arg2) => arg1+'+'+arg2
     )
   }
 }
 
-describe('Nonexistent parameters', () => {
+describe('Nonexistent metadata', () => {
   it('should work for function', () => {
     HyperFormula.getLanguage('enGB').extendFunctions({FOO: 'FOO'})
     const engine = HyperFormula.buildFromArray([

From 9afe56fda6324dca01a6590e13c31b9128e5535b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Tue, 4 Aug 2020 13:40:20 +0200
Subject: [PATCH 89/97] Update test/interpreter/function-vlookup.spec.ts

---
 test/interpreter/function-vlookup.spec.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/interpreter/function-vlookup.spec.ts b/test/interpreter/function-vlookup.spec.ts
index 1debbfe2ca..195761e4d6 100644
--- a/test/interpreter/function-vlookup.spec.ts
+++ b/test/interpreter/function-vlookup.spec.ts
@@ -14,7 +14,7 @@ const sharedExamples = (builder: (sheet: Sheet, config?: Partial<ConfigParams>)
       expect(engine.getCellValue(adr('A1'))).toEqual(detailedError(ErrorType.NA))
     })
 
-    it('too many metadata', () => {
+    it('too many parameters', () => {
       const engine = builder([
         ['=VLOOKUP(1, A2:B3, 2, TRUE(), "foo")'],
       ])

From e781c432d19b88e842c0e85684c51619369c854d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Tue, 4 Aug 2020 13:40:27 +0200
Subject: [PATCH 90/97] Update test/interpreter/function-vlookup.spec.ts

---
 test/interpreter/function-vlookup.spec.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/interpreter/function-vlookup.spec.ts b/test/interpreter/function-vlookup.spec.ts
index 195761e4d6..368c304b01 100644
--- a/test/interpreter/function-vlookup.spec.ts
+++ b/test/interpreter/function-vlookup.spec.ts
@@ -6,7 +6,7 @@ import {Sheet} from '../../src/Sheet'
 
 const sharedExamples = (builder: (sheet: Sheet, config?: Partial<ConfigParams>) => HyperFormula) => {
   describe('VLOOKUP - args validation', () => {
-    it('not enough metadata', () => {
+    it('not enough parameters', () => {
       const engine = builder([
         ['=VLOOKUP(1, A2:B3)'],
       ])

From 1fe8a7f08f0edd0d49fac115278710576f4f3eb9 Mon Sep 17 00:00:00 2001
From: izulin <izulin@gmail.com>
Date: Tue, 4 Aug 2020 14:45:31 +0200
Subject: [PATCH 91/97] merge

---
 src/interpreter/plugin/FormulaTextPlugin.ts | 13 ++++++-------
 src/interpreter/plugin/FunctionPlugin.ts    | 18 ++++++++++--------
 src/interpreter/plugin/InformationPlugin.ts | 16 ++++++----------
 3 files changed, 22 insertions(+), 25 deletions(-)

diff --git a/src/interpreter/plugin/FormulaTextPlugin.ts b/src/interpreter/plugin/FormulaTextPlugin.ts
index 9c53141bb6..b5dafd805e 100644
--- a/src/interpreter/plugin/FormulaTextPlugin.ts
+++ b/src/interpreter/plugin/FormulaTextPlugin.ts
@@ -6,16 +6,15 @@
 import {ProcedureAst} from '../../parser'
 import {CellError, ErrorType, InternalScalarValue, SimpleCellAddress} from '../../Cell'
 import {FunctionPlugin} from '../index'
+import {ArgumentTypes} from './FunctionPlugin'
 
 export class FormulaTextPlugin extends FunctionPlugin {
   public static implementedFunctions = {
     'FORMULATEXT': {
       method: 'formulatext',
-      parameters: {
-        list: [
-          {argumentType: 'noerror'}
-        ]
-      },
+      parameters: [
+          {argumentType: ArgumentTypes.NOERROR}
+        ],
       doesNotNeedArgumentsToBeComputed: true,
       isDependentOnSheetStructureChange: true
     },
@@ -30,10 +29,10 @@ export class FormulaTextPlugin extends FunctionPlugin {
    * @param formulaAddress
    * */
   public formulatext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
-    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, this.parameters('FORMULATEXT'),
+    return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, this.metadata('FORMULATEXT'),
       () => new CellError(ErrorType.NA),
       (cellReference: SimpleCellAddress) => this.serialization.getCellFormula(cellReference) || new CellError(ErrorType.NA),
       () => new CellError(ErrorType.NA)
     )
   }
-}
\ No newline at end of file
+}
diff --git a/src/interpreter/plugin/FunctionPlugin.ts b/src/interpreter/plugin/FunctionPlugin.ts
index cc4ad5056f..a7d471fbfd 100644
--- a/src/interpreter/plugin/FunctionPlugin.ts
+++ b/src/interpreter/plugin/FunctionPlugin.ts
@@ -19,13 +19,8 @@ export interface ImplementedFunctions {
   [formulaId: string]: FunctionMetadata,
 }
 
-export interface FunctionMetadata {
-  method: string,
+export interface FunctionArguments {
   parameters?: FunctionArgument[],
-  isVolatile?: boolean,
-  isDependentOnSheetStructureChange?: boolean,
-  doesNotNeedArgumentsToBeComputed?: boolean,
-
   /**
    * Used for functions with variable number of arguments -- last defined argument is repeated indefinitely.
    */
@@ -37,6 +32,13 @@ export interface FunctionMetadata {
   expandRanges?: boolean,
 }
 
+export interface FunctionMetadata extends FunctionArguments{
+  method: string,
+  isVolatile?: boolean,
+  isDependentOnSheetStructureChange?: boolean,
+  doesNotNeedArgumentsToBeComputed?: boolean,
+}
+
 export interface FunctionPluginDefinition {
   new(interpreter: Interpreter): FunctionPlugin,
 
@@ -222,7 +224,7 @@ export abstract class FunctionPlugin {
   protected runFunction = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
-    functionDefinition: FunctionMetadata,
+    functionDefinition: FunctionArguments,
     fn: (...arg: any) => InternalScalarValue
   ) => {
     const argumentDefinitions: FunctionArgument[] = functionDefinition.parameters!
@@ -275,7 +277,7 @@ export abstract class FunctionPlugin {
   protected runFunctionWithReferenceArgument = (
     args: Ast[],
     formulaAddress: SimpleCellAddress,
-    argumentDefinitions: FunctionMetadata,
+    argumentDefinitions: FunctionArguments,
     noArgCallback: () => InternalScalarValue,
     referenceCallback: (reference: SimpleCellAddress) => InternalScalarValue,
     nonReferenceCallback: (...arg: any) => InternalScalarValue
diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 5cdf95f449..af84d5eee4 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -100,20 +100,16 @@ export class InformationPlugin extends FunctionPlugin {
     },
     'SHEET': {
       method: 'sheet',
-      parameters: {
-        list: [
-          {argumentType: 'noerror'}
-        ]
-      },
+      parameters:  [
+          {argumentType: ArgumentTypes.NOERROR}
+        ],
       doesNotNeedArgumentsToBeComputed: true
     },
     'SHEETS': {
       method: 'sheets',
-      parameters: {
-        list: [
-          {argumentType: 'noerror'}
-        ]
-      },
+      parameters: [
+          {argumentType: ArgumentTypes.NOERROR}
+        ],
       doesNotNeedArgumentsToBeComputed: true
     }
   }

From 5c2eb0beeca06b6415eb765847a015f5dc3e9404 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Tue, 4 Aug 2020 15:52:22 +0200
Subject: [PATCH 92/97] Update CHANGELOG.md

Co-authored-by: Wojciech Czerniak <wojciech.czerniak@gmail.com>
---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bf09d3e0c6..b8ee239d30 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,7 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added helper methods for keeping track of cell/range dependencies: getCellPrecedents and getCellDependents. (#441)
 - Added 4 financial functions FV, PMT, PPMT, IPMT.
 - Added FORMULATEXT function.
-- Added 8 information functions ISERR, ISNA, ISREF, NA, SHEET, SHEETS, ISBINARY, ISFORMULA
+- Added 8 information functions ISERR, ISNA, ISREF, NA, SHEET, SHEETS, ISBINARY, ISFORMULA (#481)
 
 ### Changed
 - Operation `moveCells` creating cyclic dependencies does not cause losing original formula. (#479)

From e5b8da37dd36590fa109b5f81137b52116658218 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Tue, 4 Aug 2020 15:52:40 +0200
Subject: [PATCH 93/97] Update src/interpreter/plugin/InformationPlugin.ts

Co-authored-by: Wojciech Czerniak <wojciech.czerniak@gmail.com>
---
 src/interpreter/plugin/InformationPlugin.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 092d5e38aa..65e8a26de6 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -108,8 +108,8 @@ export class InformationPlugin extends FunctionPlugin {
     'SHEETS': {
       method: 'sheets',
       parameters: [
-          {argumentType: ArgumentTypes.NOERROR}
-        ],
+        {argumentType: ArgumentTypes.NOERROR}
+      ],
       doesNotNeedArgumentsToBeComputed: true
     }
   }

From e0813564a86516f20c6fa5192e678b0715467741 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Tue, 4 Aug 2020 15:52:50 +0200
Subject: [PATCH 94/97] Update src/interpreter/plugin/InformationPlugin.ts

Co-authored-by: Wojciech Czerniak <wojciech.czerniak@gmail.com>
---
 src/interpreter/plugin/InformationPlugin.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 65e8a26de6..42222c8f45 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -101,8 +101,8 @@ export class InformationPlugin extends FunctionPlugin {
     'SHEET': {
       method: 'sheet',
       parameters:  [
-          {argumentType: ArgumentTypes.NOERROR}
-        ],
+        {argumentType: ArgumentTypes.NOERROR}
+      ],
       doesNotNeedArgumentsToBeComputed: true
     },
     'SHEETS': {

From 6f7032d59541b9dc71b971326eca3bda9f8f6ba8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Tue, 4 Aug 2020 15:53:02 +0200
Subject: [PATCH 95/97] Update src/interpreter/plugin/InformationPlugin.ts

Co-authored-by: Wojciech Czerniak <wojciech.czerniak@gmail.com>
---
 src/interpreter/plugin/InformationPlugin.ts | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/interpreter/plugin/InformationPlugin.ts b/src/interpreter/plugin/InformationPlugin.ts
index 42222c8f45..cba11aeeb4 100644
--- a/src/interpreter/plugin/InformationPlugin.ts
+++ b/src/interpreter/plugin/InformationPlugin.ts
@@ -23,33 +23,33 @@ export class InformationPlugin extends FunctionPlugin {
     'ISBINARY': {
       method: 'isbinary',
       parameters: [
-          {argumentType: ArgumentTypes.STRING}
-        ]
+        {argumentType: ArgumentTypes.STRING}
+      ]
     },
     'ISERR': {
       method: 'iserr',
       parameters:  [
-          {argumentType: ArgumentTypes.SCALAR}
-        ]
+        {argumentType: ArgumentTypes.SCALAR}
+      ]
     },
     'ISFORMULA': {
       method: 'isformula',
       parameters:  [
-          {argumentType: ArgumentTypes.NOERROR}
-        ],
+        {argumentType: ArgumentTypes.NOERROR}
+      ],
       doesNotNeedArgumentsToBeComputed: true
     },
     'ISNA': {
       method: 'isna',
       parameters: [
-          {argumentType: ArgumentTypes.SCALAR}
-        ]
+        {argumentType: ArgumentTypes.SCALAR}
+      ]
     },
     'ISREF': {
       method: 'isref',
       parameters:[
-          {argumentType: ArgumentTypes.SCALAR}
-        ]
+        {argumentType: ArgumentTypes.SCALAR}
+      ]
     },
     'ISERROR': {
       method: 'iserror',

From bbd74dc382e62c01a3d83b895816be33c5277fbe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Tue, 4 Aug 2020 15:53:17 +0200
Subject: [PATCH 96/97] Update src/interpreter/plugin/FormulaTextPlugin.ts

Co-authored-by: Wojciech Czerniak <wojciech.czerniak@gmail.com>
---
 src/interpreter/plugin/FormulaTextPlugin.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/interpreter/plugin/FormulaTextPlugin.ts b/src/interpreter/plugin/FormulaTextPlugin.ts
index b5dafd805e..bbcdb685ed 100644
--- a/src/interpreter/plugin/FormulaTextPlugin.ts
+++ b/src/interpreter/plugin/FormulaTextPlugin.ts
@@ -27,7 +27,7 @@ export class FormulaTextPlugin extends FunctionPlugin {
    *
    * @param ast
    * @param formulaAddress
-   * */
+   */
   public formulatext(ast: ProcedureAst, formulaAddress: SimpleCellAddress): InternalScalarValue {
     return this.runFunctionWithReferenceArgument(ast.args, formulaAddress, this.metadata('FORMULATEXT'),
       () => new CellError(ErrorType.NA),

From c550f5b7d74de8bb24ed1c7dde200c5261ca0bf7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Przemys=C5=82aw=20Uzna=C5=84ski?=
 <40573492+izulin@users.noreply.github.com>
Date: Tue, 4 Aug 2020 15:53:45 +0200
Subject: [PATCH 97/97] Update src/interpreter/plugin/FormulaTextPlugin.ts

Co-authored-by: Wojciech Czerniak <wojciech.czerniak@gmail.com>
---
 src/interpreter/plugin/FormulaTextPlugin.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/interpreter/plugin/FormulaTextPlugin.ts b/src/interpreter/plugin/FormulaTextPlugin.ts
index bbcdb685ed..23cae60840 100644
--- a/src/interpreter/plugin/FormulaTextPlugin.ts
+++ b/src/interpreter/plugin/FormulaTextPlugin.ts
@@ -13,8 +13,8 @@ export class FormulaTextPlugin extends FunctionPlugin {
     'FORMULATEXT': {
       method: 'formulatext',
       parameters: [
-          {argumentType: ArgumentTypes.NOERROR}
-        ],
+        {argumentType: ArgumentTypes.NOERROR}
+      ],
       doesNotNeedArgumentsToBeComputed: true,
       isDependentOnSheetStructureChange: true
     },