WI #2236 Limit uses of ImmutableList<T> (#2575)

TypeCobolTeam · Sep 21, 2023 · dcac1dd · dcac1dd
1 parent be0a114
commit dcac1dd
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Showing 9 changed files with 81 additions and 599 deletions.
diff --git a/TypeCobol.Test/Parser/Scanner/ScannerUtils.cs b/TypeCobol.Test/Parser/Scanner/ScannerUtils.cs
@@ -80,7 +80,7 @@ public static string ScanLines(TokensLine[] tokensLines)
             tokensLinesList.AddRange(tokensLines);
 
             var initialScanState = new MultilineScanState(TextSourceInfo.EncodingForAlphanumericLiterals);
-            ScannerStep.ScanDocument(TextSourceInfo, tokensLinesList, CompilerOptions, CopyTextNameVariations, initialScanState);
+            ScannerStep.ScanDocument(TextSourceInfo, tokensLinesList.ToImmutable(), CompilerOptions, CopyTextNameVariations, initialScanState);
 
             StringBuilder sbResult = new StringBuilder();
             for (int i = 0; i < tokensLines.Length; i++)

diff --git a/TypeCobol/Compiler/CodeModel/SymbolTable.cs b/TypeCobol/Compiler/CodeModel/SymbolTable.cs
@@ -14,9 +14,9 @@ namespace TypeCobol.Compiler.CodeModel
 {
     public class SymbolTable
     {
-        private static readonly IList<Section> EmptySectionList = new ImmutableList<Section>();
-        private static readonly IList<Paragraph> EmptyParagraphList = new ImmutableList<Paragraph>();
-        private static readonly IList<TypeDefinition> EmptyTypeDefinitionList = new ImmutableList<TypeDefinition>();
+        private static readonly IList<Section> EmptySectionList = ImmutableList<Section>.Empty;
+        private static readonly IList<Paragraph> EmptyParagraphList = ImmutableList<Paragraph>.Empty;
+        private static readonly IList<TypeDefinition> EmptyTypeDefinitionList = ImmutableList<TypeDefinition>.Empty;
 
         public Scope CurrentScope { get; }
         public SymbolTable EnclosingScope { get; }

diff --git a/TypeCobol/Compiler/CompilationDocument.cs b/TypeCobol/Compiler/CompilationDocument.cs
@@ -514,7 +514,7 @@ private void ApplyTextChange(TextChange textChange, IList<DocumentChange<ICobolT
         private void ShiftLines(int startIndex, int offset)
         {
             Debug.Assert(offset != 0);
-            using (var enumerator = compilationDocumentLines.GetEnumerator(startIndex, -1, false))
+            using (var enumerator = compilationDocumentLines.GetEnumerator(startIndex, false))
             {
                 //Loop on every line that appear after target line and shift them according to given offset
                 while (enumerator.MoveNext())
@@ -697,6 +697,7 @@ public void RefreshTokensDocumentSnapshot()
                 // Create a new snapshot only if things changed since last snapshot
                 if (TokensDocumentSnapshot == null || TokensDocumentSnapshot.CurrentVersion != currentTokensLinesVersion)
                 {
+                    // Freeze compilationDocumentLines into an ImmutableList as further steps won't need to modify it
                     TokensDocumentSnapshot = new TokensDocument(TextSourceInfo, textLinesVersionForCurrentTokensLines, currentTokensLinesVersion, compilationDocumentLines.ToImmutable());
                 }
             }
@@ -755,7 +756,7 @@ public void RefreshProcessedTokensDocumentSnapshot()
                     if (tokensDocument != null)
                     {
                         // Process all lines of the document for the first time
-                        PreprocessorStep.ProcessDocument(this, ((ImmutableList<CodeElementsLine>)tokensDocument.Lines), _documentImporter, perfStatsForParserInvocation, out missingCopies);
+                        PreprocessorStep.ProcessDocument(this, (ISearchableReadOnlyList<ProcessedTokensLine>)tokensDocument.Lines, _documentImporter, perfStatsForParserInvocation, out missingCopies);
 
                         // Create the first processed tokens document snapshot
                         ProcessedTokensDocumentSnapshot = CreateProcessedTokensDocument(new DocumentVersion<IProcessedTokensLine>(this), (ISearchableReadOnlyList<CodeElementsLine>) tokensDocument.Lines);
@@ -768,9 +769,8 @@ public void RefreshProcessedTokensDocumentSnapshot()
                 }
                 else
                 {
-                    ImmutableList<CodeElementsLine>.Builder processedTokensDocumentLines = ((ImmutableList<CodeElementsLine>) tokensDocument.Lines).ToBuilder();
                     IList<DocumentChange<IProcessedTokensLine>> documentChanges = PreprocessorStep.ProcessChanges(this,
-                        processedTokensDocumentLines, tokensLineChanges, PrepareDocumentLineForUpdate,
+                        (ISearchableReadOnlyList<ProcessedTokensLine>)tokensDocument.Lines, tokensLineChanges, PrepareDocumentLineForUpdate,
                         _documentImporter, perfStatsForParserInvocation, out missingCopies);
 
                     // Create a new version of the document to track these changes
@@ -783,7 +783,7 @@ public void RefreshProcessedTokensDocumentSnapshot()
                     currentProcessedTokensLineVersion = currentProcessedTokensLineVersion.next;
 
                     // Update the processed tokens document snapshot
-                    ProcessedTokensDocumentSnapshot = CreateProcessedTokensDocument(currentProcessedTokensLineVersion, processedTokensDocumentLines.ToImmutable());
+                    ProcessedTokensDocumentSnapshot = CreateProcessedTokensDocument(currentProcessedTokensLineVersion, (ISearchableReadOnlyList<CodeElementsLine>)tokensDocument.Lines);
                 }
 
                 ProcessedTokensDocument CreateProcessedTokensDocument(DocumentVersion<IProcessedTokensLine> version, ISearchableReadOnlyList<CodeElementsLine> lines)

diff --git a/TypeCobol/Compiler/CompilationUnit.cs b/TypeCobol/Compiler/CompilationUnit.cs
@@ -100,7 +100,7 @@ public void RefreshCodeElementsDocumentSnapshot()
                         CodeElementsParserStep.ParseDocument(processedTokensDocument, CompilerOptions, perfStatsForParserInvocation);
 
                         // Create the first code elements document snapshot
-                        CodeElementsDocumentSnapshot = new CodeElementsDocument(processedTokensDocument, new DocumentVersion<ICodeElementsLine>(this), ((ImmutableList<CodeElementsLine>)processedTokensDocument.Lines));
+                        CodeElementsDocumentSnapshot = new CodeElementsDocument(processedTokensDocument, new DocumentVersion<ICodeElementsLine>(this), (ISearchableReadOnlyList<ICodeElementsLine>)processedTokensDocument.Lines);
                     }
                 }
                 else
@@ -117,8 +117,7 @@ public void RefreshCodeElementsDocumentSnapshot()
                     currentCodeElementsLinesVersion = currentCodeElementsLinesVersion.next;
 
                     // Update the code elements document snapshot
-                    ImmutableList<CodeElementsLine>.Builder codeElementsDocumentLines = ((ImmutableList<CodeElementsLine>)processedTokensDocument.Lines).ToBuilder();
-                    CodeElementsDocumentSnapshot = new CodeElementsDocument(processedTokensDocument, currentCodeElementsLinesVersion, codeElementsDocumentLines.ToImmutable());
+                    CodeElementsDocumentSnapshot = new CodeElementsDocument(processedTokensDocument, currentCodeElementsLinesVersion, (ISearchableReadOnlyList<ICodeElementsLine>)processedTokensDocument.Lines);
                 }
 
                 // Stop perf measurement
@@ -258,10 +257,9 @@ public void ProduceTemporarySemanticDocument()
                     var customAnalyzers = _analyzerProvider?.CreateSyntaxDrivenAnalyzers(CompilerOptions, TextSourceInfo);
 
                     // Program and Class parsing is not incremental : the objects are rebuilt each time this method is called
-                    //TODO cast to ImmutableList<CodeElementsLine> sometimes fails here
                     ProgramClassParserStep.CupParseProgramOrClass(
                         TextSourceInfo,
-                        (ImmutableList<CodeElementsLine>) codeElementsDocument.Lines,
+                        (ISearchableReadOnlyList<CodeElementsLine>) codeElementsDocument.Lines,
                         CompilerOptions,
                         CustomSymbols,
                         perfStatsForParserInvocation,