Merge pull request dotnet#61529 from CyrusNajmabadi/aspEmbeddedChars

Expose VirtualChars to asp.net (through EA) to facilitate route classification

src/Tools/ExternalAccess/AspNetCore/EmbeddedLanguages/AspNetCoreEmbeddedLanguageClassificationContext.cs

@@ -12,9 +12,12 @@ internal readonly struct AspNetCoreEmbeddedLanguageClassificationContext
     {
         private readonly EmbeddedLanguageClassificationContext _context;
 
-        public AspNetCoreEmbeddedLanguageClassificationContext(EmbeddedLanguageClassificationContext context)
+        internal AspNetCoreEmbeddedLanguageClassificationContext(
+            EmbeddedLanguageClassificationContext context,
+            AspNetCoreVirtualCharSequence virtualCharSequence)
         {
             _context = context;
+            VirtualCharSequence = virtualCharSequence;
         }
 
         /// <inheritdoc cref="EmbeddedLanguageClassificationContext.SyntaxToken"/>
@@ -23,6 +26,9 @@ public AspNetCoreEmbeddedLanguageClassificationContext(EmbeddedLanguageClassific
         /// <inheritdoc cref="EmbeddedLanguageClassificationContext.SemanticModel"/>
         public SemanticModel SemanticModel => _context.SemanticModel;
 
+        /// <inheritdoc cref="Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars.VirtualCharSequence"/>
+        public AspNetCoreVirtualCharSequence VirtualCharSequence { get; }
+
         /// <inheritdoc cref="EmbeddedLanguageClassificationContext.CancellationToken"/>
         public CancellationToken CancellationToken => _context.CancellationToken;
 

src/Tools/ExternalAccess/AspNetCore/EmbeddedLanguages/AspNetCoreVirtualChar.cs

@@ -0,0 +1,32 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Text;
+using Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.CodeAnalysis.ExternalAccess.AspNetCore.EmbeddedLanguages
+{
+    internal readonly struct AspNetCoreVirtualChar
+    {
+        private readonly VirtualChar _virtualChar;
+
+        internal AspNetCoreVirtualChar(VirtualChar virtualChar)
+        {
+            _virtualChar = virtualChar;
+        }
+
+        /// <inheritdoc cref="VirtualChar.Rune"/>
+        public Rune Rune => _virtualChar.Rune;
+
+        /// <inheritdoc cref="VirtualChar.SurrogateChar"/>
+        public char SurrogateChar => _virtualChar.SurrogateChar;
+
+        /// <inheritdoc cref="VirtualChar.Span"/>
+        public TextSpan Span => _virtualChar.Span;
+
+        /// <inheritdoc cref="VirtualChar.Value"/>
+        public int Value => _virtualChar.Value;
+    }
+}

src/Tools/ExternalAccess/AspNetCore/EmbeddedLanguages/AspNetCoreVirtualCharSequence.cs

@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars;
+
+namespace Microsoft.CodeAnalysis.ExternalAccess.AspNetCore.EmbeddedLanguages
+{
+    /// <inheritdoc cref="VirtualCharSequence"/>
+    internal readonly struct AspNetCoreVirtualCharSequence
+    {
+        private readonly VirtualCharSequence _virtualCharSequence;
+
+        internal AspNetCoreVirtualCharSequence(VirtualCharSequence virtualCharSequence)
+        {
+            _virtualCharSequence = virtualCharSequence;
+        }
+
+        /// <inheritdoc cref="VirtualCharSequence.Length"/>
+        public int Length => _virtualCharSequence.Length;
+
+        /// <inheritdoc cref="VirtualCharSequence.this"/>
+        public AspNetCoreVirtualChar this[int index] => new(_virtualCharSequence[index]);
+    }
+}

src/Tools/ExternalAccess/AspNetCore/Internal/EmbeddedLanguages/AspNetCoreEmbeddedLanguageClassifier.cs

@@ -28,7 +28,15 @@ public void RegisterClassifications(EmbeddedLanguageClassificationContext contex
                 return;
 
             var classifiers = AspNetCoreClassifierExtensionProvider.GetExtensions(context.Project);
-            var aspContext = new AspNetCoreEmbeddedLanguageClassificationContext(context);
+            if (classifiers.Length == 0)
+                return;
+
+            var virtualChars = context.VirtualCharService.TryConvertToVirtualChars(context.SyntaxToken);
+            if (virtualChars.IsDefaultOrEmpty)
+                return;
+
+            var aspContext = new AspNetCoreEmbeddedLanguageClassificationContext(
+                context, new AspNetCoreVirtualCharSequence(virtualChars));
             foreach (var classifier in classifiers)
                 classifier.RegisterClassifications(aspContext);
         }

src/Workspaces/Core/Portable/Classification/EmbeddedLanguages/AbstractEmbeddedLanguageClassificationService.cs

@@ -42,6 +42,11 @@ internal abstract class AbstractEmbeddedLanguageClassificationService : IEmbedde
         /// </summary>
         private readonly Dictionary<string, ArrayBuilder<Lazy<IEmbeddedLanguageClassifier, EmbeddedLanguageMetadata>>> _identifierToClassifiers = new(StringComparer.OrdinalIgnoreCase);
 
+        /// <summary>
+        /// Information about the embedded language.
+        /// </summary>
+        private readonly EmbeddedLanguageInfo _info;
+
         /// <summary>
         /// Helper to look at string literals and determine what language they are annotated to take.
         /// </summary>
@@ -71,6 +76,7 @@ protected AbstractEmbeddedLanguageClassificationService(
             foreach (var (_, classifiers) in _identifierToClassifiers)
                 classifiers.RemoveDuplicates();
 
+            _info = info;
             _detector = new EmbeddedLanguageDetector(info, _identifierToClassifiers.Keys.ToImmutableArray());
 
             _syntaxTokenKinds.Add(syntaxKinds.CharacterLiteralToken);
@@ -165,7 +171,7 @@ private void ClassifyToken(SyntaxToken token)
                     _classifierBuffer.Clear();
 
                     var context = new EmbeddedLanguageClassificationContext(
-                        _project, _semanticModel, token, _options, _result, _cancellationToken);
+                        _project, _semanticModel, token, _options, _service._info.VirtualCharService, _result, _cancellationToken);
 
                     // First, see if this is a string annotated with either a comment or [StringSyntax] attribute. If
                     // so, delegate to the first classifier we have registered for whatever language ID we find.

src/Workspaces/Core/Portable/Classification/EmbeddedLanguages/EmbeddedLanguageClassifierContext.cs

@@ -4,14 +4,14 @@
 
 using System.Threading;
 using Microsoft.CodeAnalysis.Classification;
+using Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.CodeAnalysis.Text;
 
 namespace Microsoft.CodeAnalysis.Classification
 {
     internal struct EmbeddedLanguageClassificationContext
     {
-        internal readonly ClassificationOptions Options;
         private readonly ArrayBuilder<ClassifiedSpan> _result;
 
         public Project? Project { get; }
@@ -28,18 +28,23 @@ internal struct EmbeddedLanguageClassificationContext
 
         public CancellationToken CancellationToken { get; }
 
+        internal readonly ClassificationOptions Options;
+        internal readonly IVirtualCharService VirtualCharService;
+
         internal EmbeddedLanguageClassificationContext(
             Project? project,
             SemanticModel semanticModel,
             SyntaxToken syntaxToken,
             ClassificationOptions options,
+            IVirtualCharService virtualCharService,
             ArrayBuilder<ClassifiedSpan> result,
             CancellationToken cancellationToken)
         {
             Project = project;
             SemanticModel = semanticModel;
             SyntaxToken = syntaxToken;
             Options = options;
+            VirtualCharService = virtualCharService;
             _result = result;
             CancellationToken = cancellationToken;
         }

src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/EmbeddedLanguages/VirtualChars/VirtualCharSequence.cs

@@ -63,7 +63,14 @@ private VirtualCharSequence(Chunk sequence, TextSpan span)
             _span = span;
         }
 
+        /// <summary>
+        /// Gets the number of elements contained in the <see cref="VirtualCharSequence"/>.
+        /// </summary>
         public int Length => _span.Length;
+
+        /// <summary>
+        /// Gets the <see cref="VirtualChar"/> at the specified index.
+        /// </summary>
         public VirtualChar this[int index] => _leafCharacters[_span.Start + index];
 
         public bool IsDefault => _leafCharacters == null;