Make types sealed.

src/Workspaces/Core/Portable/EmbeddedLanguages/RegularExpressions/LanguageServices/RegexEmbeddedBraceMatcher.cs

@@ -11,12 +11,10 @@
 
 namespace Microsoft.CodeAnalysis.EmbeddedLanguages.RegularExpressions.LanguageServices
 {
-    using RegexToken = EmbeddedSyntaxToken<RegexKind>;
-
     /// <summary>
     /// Brace matching impl for embedded regex strings.
     /// </summary>
-    internal class RegexEmbeddedBraceMatcher : IEmbeddedBraceMatcher
+    internal sealed class RegexEmbeddedBraceMatcher : IEmbeddedBraceMatcher
     {
         private readonly RegexEmbeddedLanguage _language;
 

src/Workspaces/Core/Portable/EmbeddedLanguages/RegularExpressions/LanguageServices/RegexEmbeddedClassifier.cs

@@ -9,8 +9,6 @@
 
 namespace Microsoft.CodeAnalysis.EmbeddedLanguages.RegularExpressions.LanguageServices
 {
-    using Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars;
-    using Microsoft.CodeAnalysis.LanguageServices;
     using static EmbeddedSyntaxHelpers;
 
     using RegexToken = EmbeddedSyntaxToken<RegexKind>;
@@ -19,7 +17,7 @@ namespace Microsoft.CodeAnalysis.EmbeddedLanguages.RegularExpressions.LanguageSe
     /// <summary>
     /// Classifier impl for embedded regex strings.
     /// </summary>
-    internal class RegexEmbeddedClassifier : IEmbeddedClassifier
+    internal sealed class RegexEmbeddedClassifier : IEmbeddedClassifier
     {
         private static ObjectPool<Visitor> _visitorPool = new ObjectPool<Visitor>(() => new Visitor());
 

src/Workspaces/Core/Portable/EmbeddedLanguages/RegularExpressions/LanguageServices/RegexEmbeddedHighlighter.cs

@@ -14,7 +14,7 @@ namespace Microsoft.CodeAnalysis.EmbeddedLanguages.RegularExpressions.LanguageSe
 {
     using RegexToken = EmbeddedSyntaxToken<RegexKind>;
 
-    internal class RegexEmbeddedHighlighter : IEmbeddedHighlighter
+    internal sealed class RegexEmbeddedHighlighter : IEmbeddedHighlighter
     {
         private readonly RegexEmbeddedLanguage _language;
 

src/Workspaces/Core/Portable/EmbeddedLanguages/RegularExpressions/LanguageServices/RegexPatternDetector.cs

@@ -8,7 +8,6 @@
 using System.Runtime.CompilerServices;
 using System.Text.RegularExpressions;
 using System.Threading;
-using Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars;
 using Microsoft.CodeAnalysis.LanguageServices;
 using Microsoft.CodeAnalysis.Shared.Extensions;
 using Roslyn.Utilities;
@@ -18,7 +17,7 @@ namespace Microsoft.CodeAnalysis.EmbeddedLanguages.RegularExpressions.LanguageSe
     /// <summary>
     /// Helper class to detect regex pattern tokens in a document efficiently.
     /// </summary>
-    internal class RegexPatternDetector
+    internal sealed class RegexPatternDetector
     {
         private const string _patternName = "pattern";