feat: add isCharAndNotRestricted to xml/1.1/ed2

src/xml/1.1/ed2.ts

@@ -81,6 +81,28 @@ export function isRestrictedChar(c: number): boolean {
     (c >= 0x86 && c <= 0x9F);
 }
 
+/**
+ * Determines whether a codepoint matches the ``CHAR`` production and does not
+ * match the ``RESTRICTED_CHAR`` production. ``isCharAndNotRestricted(x)`` is
+ * equivalent to ``isChar(x) && !isRestrictedChar(x)``. This function is faster
+ * than running the two-call equivalent.
+ *
+ * @param c The code point.
+ *
+ * @returns ``true`` if the codepoint matches ``CHAR`` and does not match
+ * ``RESTRICTED_CHAR``.
+ */
+export function isCharAndNotRestricted(c: number): boolean {
+  return (c === 0x9) ||
+    (c === 0xA) ||
+    (c === 0xD) ||
+    (c > 0x1F && c < 0x7F) ||
+    (c === 0x85) ||
+    (c > 0x9F && c <= 0xD7FF) ||
+    (c >= 0xE000 && c <= 0xFFFD) ||
+    (c >= 0x10000 && c <= 0x10FFFF);
+}
+
 /**
  * Determines whether a codepoint matches the ``S`` (space) production.
  *

test/xmlchars.spec.ts

@@ -324,6 +324,12 @@ describe("xml/1.1", () => {
       },
     };
 
+    // tslint:disable-next-line:mocha-no-side-effect-code
+    const isCharAndNotRestrictedCase: Case = {
+      matching: cases.CHAR_RE.matching
+        .filter(c => !cases.RESTRICTED_CHAR_RE.matching.includes(c)),
+    };
+
     describe("regexes", () => {
       // tslint:disable-next-line:mocha-no-side-effect-code
       for (const name of (Object.keys(cases) as (keyof typeof cases)[])) {
@@ -345,6 +351,12 @@ describe("xml/1.1", () => {
                              cases.RESTRICTED_CHAR_RE);
     });
 
+    describe(".isCharAndNotRestricted", () => {
+      // tslint:disable-next-line:mocha-no-side-effect-code
+      makeCodePointTestTests(xml_1_1_ed2.isCharAndNotRestricted,
+                             isCharAndNotRestrictedCase);
+    });
+
     describe(".isS", () => {
       // tslint:disable-next-line:mocha-no-side-effect-code
       makeCodePointTestTests(xml_1_1_ed2.isS, cases.S_RE);