From e02333a54be86f158de190b8ff3544eb0089404c Mon Sep 17 00:00:00 2001
From: Enkidu93 <lowryec17@gcc.edu>
Date: Mon, 30 Sep 2024 14:31:08 -0400
Subject: [PATCH] Add row filter text

---
 src/SIL.Machine/Corpora/CorporaExtensions.cs | 28 ++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/SIL.Machine/Corpora/CorporaExtensions.cs b/src/SIL.Machine/Corpora/CorporaExtensions.cs
index 7d974366e..1012c6cd9 100644
--- a/src/SIL.Machine/Corpora/CorporaExtensions.cs
+++ b/src/SIL.Machine/Corpora/CorporaExtensions.cs
@@ -209,6 +209,11 @@ public static ITextCorpus FilterTexts(this ITextCorpus corpus, Func<IText, bool>
             return new TextFilterTextCorpus(corpus, predicate);
         }
 
+        public static ITextCorpus FilterTextRows(this ITextCorpus corpus, Func<TextRow, bool> predicate)
+        {
+            return new RowFilterTextCorpus(corpus, predicate);
+        }
+
         public static ITextCorpus WhereNonempty(this ITextCorpus corpus)
         {
             return corpus.Where(r => !r.IsEmpty);
@@ -442,6 +447,29 @@ public override IEnumerable<TextRow> GetRows(IEnumerable<string> textIds)
             }
         }
 
+        private class RowFilterTextCorpus : TextCorpusBase
+        {
+            private readonly ITextCorpus _corpus;
+            private readonly Func<TextRow, bool> _predicate;
+
+            public RowFilterTextCorpus(ITextCorpus corpus, Func<TextRow, bool> predicate)
+            {
+                _corpus = corpus;
+                _predicate = predicate;
+            }
+
+            public override IEnumerable<IText> Texts => _corpus.Texts;
+
+            public override bool IsTokenized => _corpus.IsTokenized;
+
+            public override ScrVers Versification => _corpus.Versification;
+
+            public override IEnumerable<TextRow> GetRows(IEnumerable<string> textIds)
+            {
+                return _corpus.GetRows(textIds ?? Texts.Select(t => t.Id)).Where(_predicate);
+            }
+        }
+
         private class TakeTextCorpus : TextCorpusBase
         {
             private readonly ITextCorpus _corpus;