Revert json features. They will be added in the jsonFeatures branch

src/EditorFeatures/CSharp/BraceMatching/CSharpJsonBraceMatcher.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.Editor.Implementation.BraceMatching;
-
-namespace Microsoft.CodeAnalysis.Editor.CSharp.BraceMatching
-{
-    [ExportBraceMatcher(LanguageNames.CSharp)]
-    internal class CSharpJsonBraceMatcher : IBraceMatcher
-    {
-        public Task<BraceMatchingResult?> FindBracesAsync(Document document, int position, CancellationToken cancellationToken)
-            => CommonJsonBraceMatcher.FindBracesAsync(document, position, cancellationToken);
-    }
-}

src/EditorFeatures/CSharp/BraceMatching/CSharpRegexBraceMatcher.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.Editor.Implementation.BraceMatching;
-
-namespace Microsoft.CodeAnalysis.Editor.CSharp.BraceMatching
-{
-    [ExportBraceMatcher(LanguageNames.CSharp)]
-    internal class CSharpRegexBraceMatcher : IBraceMatcher
-    {
-        public Task<BraceMatchingResult?> FindBracesAsync(Document document, int position, CancellationToken cancellationToken)
-            => CommonRegexBraceMatcher.FindBracesAsync(document, position, cancellationToken);
-    }
-}

src/EditorFeatures/CSharpTest/JsonStringDetector/JsonStringDetectorTests.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.CodeFixes;
-using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.CSharp.JsonStringDetector;
-using Microsoft.CodeAnalysis.Diagnostics;
-using Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Diagnostics;
-using Roslyn.Test.Utilities;
-using Xunit;
-
-namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.JsonStringDetector
-{
-    public class JsonStringDetectorTests : AbstractCSharpDiagnosticProviderBasedUserDiagnosticTest
-    {
-        internal override (DiagnosticAnalyzer, CodeFixProvider) CreateDiagnosticProviderAndFixer(Workspace workspace)
-            => (new CSharpJsonStringDetectorDiagnosticAnalyzer(), new CSharpEnableIDEJsonFeaturesCodeFixProvider());
-         
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsDetectJsonString)]
-        public async Task TestStrict()
-        {
-            await TestInRegularAndScriptAsync(
-@"
-class C
-{
-    void Goo()
-    {
-        var j = [||]""{ \""a\"": 0 }"";
-    }
-}",
-@"
-class C
-{
-    void Goo()
-    {
-        var j = /*lang=json,strict*/ ""{ \""a\"": 0 }"";
-    }
-}");
-        }
-
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsDetectJsonString)]
-        public async Task TestNonStrict()
-        {
-            await TestInRegularAndScriptAsync(
-@"
-class C
-{
-    void Goo()
-    {
-        var j = [||]""{ 'a': 00 }"";
-    }
-}",
-@"
-class C
-{
-    void Goo()
-    {
-        var j = /*lang=json*/ ""{ 'a': 00 }"";
-    }
-}");
-        }
-    }
-}

src/EditorFeatures/CSharpTest/ValidateJsonString/ValidateJsonStringTests.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.CodeFixes;
-using Microsoft.CodeAnalysis.CSharp.ValidateJsonString;
-using Microsoft.CodeAnalysis.Diagnostics;
-using Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Diagnostics;
-using Microsoft.CodeAnalysis.Options;
-using Microsoft.CodeAnalysis.Json;
-using Roslyn.Test.Utilities;
-using Xunit;
-
-namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.ValidateJsonString
-{
-    public class ValidateJsonStringTests : AbstractCSharpDiagnosticProviderBasedUserDiagnosticTest
-    {
-        internal override (DiagnosticAnalyzer, CodeFixProvider) CreateDiagnosticProviderAndFixer(Workspace workspace)
-            => (new CSharpValidateJsonStringDiagnosticAnalyzer(), null);
-
-        private IDictionary<OptionKey, object> OptionOn()
-        {
-            var optionsSet = new Dictionary<OptionKey, object>();
-            optionsSet.Add(new OptionKey(JsonOptions.ReportInvalidJsonPatterns, LanguageNames.CSharp), true);
-            optionsSet.Add(new OptionKey(JsonOptions.ReportInvalidJsonPatterns, LanguageNames.VisualBasic), true);
-            return optionsSet;
-        }
-
-        [Fact, Trait(Traits.Feature, Traits.Features.ValidateJsonString)]
-        public async Task TestWarning1()
-        {
-            await TestDiagnosticInfoAsync(@"
-class Program
-{
-    void Main()
-    {
-        var r = /*lang=json,strict*/ ""[|new|] Json()"";
-    }     
-}",
-                options: OptionOn(),
-                diagnosticId: IDEDiagnosticIds.JsonPatternDiagnosticId,
-                diagnosticSeverity: DiagnosticSeverity.Warning,
-                diagnosticMessage: string.Format(FeaturesResources.JSON_issue_0, WorkspacesResources.Constructors_not_allowed));
-        }
-
-        [Fact, Trait(Traits.Feature, Traits.Features.ValidateJsonString)]
-        public async Task TestWarning2()
-        {
-            await TestDiagnosticInfoAsync(@"
-class Program
-{
-    void Main()
-    {
-        var r = /*lang=json*/ ""[|}|]"";
-    }     
-}",
-                options: OptionOn(),
-                diagnosticId: IDEDiagnosticIds.JsonPatternDiagnosticId,
-                diagnosticSeverity: DiagnosticSeverity.Warning,
-                diagnosticMessage: string.Format(FeaturesResources.JSON_issue_0, 
-                    string.Format(WorkspacesResources._0_unexpected, '}')));
-        }
-    }
-}

src/EditorFeatures/CSharpTest/ValidateRegexString/ValidateRegexStringTests.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.CodeFixes;
-using Microsoft.CodeAnalysis.CSharp.ValidateRegexString;
-using Microsoft.CodeAnalysis.Diagnostics;
-using Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Diagnostics;
-using Microsoft.CodeAnalysis.Options;
-using Microsoft.CodeAnalysis.RegularExpressions;
-using Roslyn.Test.Utilities;
-using Xunit;
-
-namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.ValidateRegexString
-{
-    public class ValidateRegexStringTests : AbstractCSharpDiagnosticProviderBasedUserDiagnosticTest
-    {
-        internal override (DiagnosticAnalyzer, CodeFixProvider) CreateDiagnosticProviderAndFixer(Workspace workspace)
-            => (new CSharpValidateRegexStringDiagnosticAnalyzer(), null);
-
-        private IDictionary<OptionKey, object> OptionOn()
-        {
-            var optionsSet = new Dictionary<OptionKey, object>();
-            optionsSet.Add(new OptionKey(RegularExpressionsOptions.ReportInvalidRegexPatterns, LanguageNames.CSharp), true);
-            optionsSet.Add(new OptionKey(RegularExpressionsOptions.ReportInvalidRegexPatterns, LanguageNames.VisualBasic), true);
-            return optionsSet;
-        }
-
-        private IDictionary<OptionKey, object> OptionOff()
-        {
-            var optionsSet = new Dictionary<OptionKey, object>();
-            optionsSet.Add(new OptionKey(RegularExpressionsOptions.ReportInvalidRegexPatterns, LanguageNames.CSharp), false);
-            optionsSet.Add(new OptionKey(RegularExpressionsOptions.ReportInvalidRegexPatterns, LanguageNames.VisualBasic), false);
-            return optionsSet;
-        }
-
-        [Fact, Trait(Traits.Feature, Traits.Features.ValidateRegexString)]
-        public async Task TestWarning1()
-        {
-            await TestDiagnosticInfoAsync(@"
-using System.Text.RegularExpressions;
-
-class Program
-{
-    void Main()
-    {
-        var r = new Regex(@""[|)|]"");
-    }     
-}",
-                options: OptionOn(),
-                diagnosticId: IDEDiagnosticIds.RegexPatternDiagnosticId,
-                diagnosticSeverity: DiagnosticSeverity.Warning,
-                diagnosticMessage: string.Format(FeaturesResources.Regex_issue_0, WorkspacesResources.Too_many_close_parens));
-        }
-
-        [Fact, Trait(Traits.Feature, Traits.Features.ValidateRegexString)]
-        public async Task TestWarning2()
-        {
-            await TestDiagnosticInfoAsync(@"
-using System.Text.RegularExpressions;
-
-class Program
-{
-    void Main()
-    {
-        var r = new Regex(""[|\u0029|]"");
-    }     
-}",
-                options: OptionOn(),
-                diagnosticId: IDEDiagnosticIds.RegexPatternDiagnosticId,
-                diagnosticSeverity: DiagnosticSeverity.Warning,
-                diagnosticMessage: string.Format(FeaturesResources.Regex_issue_0, WorkspacesResources.Too_many_close_parens));
-        }
-
-        [Fact, Trait(Traits.Feature, Traits.Features.ValidateRegexString)]
-        public async Task TestWarningMissing1()
-        {
-            await TestDiagnosticMissingAsync(@"
-using System.Text.RegularExpressions;
-
-class Program
-{
-    void Main()
-    {
-        var r = new Regex(@""[|\u0029|]"");
-    }     
-}");
-        }
-    }
-}

src/EditorFeatures/Core/Implementation/BraceMatching/CommonJsonBraceMatcher.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.Json;
-using Microsoft.CodeAnalysis.LanguageServices;
-using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.VirtualChars;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.Editor.Implementation.BraceMatching
-{
-    internal static class CommonJsonBraceMatcher
-    {
-        internal static async Task<BraceMatchingResult?> FindBracesAsync(
-            Document document, int position, CancellationToken cancellationToken)
-        {
-            var option = document.Project.Solution.Workspace.Options.GetOption(JsonOptions.HighlightRelatedJsonComponentsUnderCursor, document.Project.Language);
-            if (!option)
-            {
-                return default;
-            }
-
-            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
-            var token = root.FindToken(position);
-
-            var syntaxFacts = document.GetLanguageService<ISyntaxFactsService>();
-            if (JsonPatternDetector.IsDefinitelyNotJson(token, syntaxFacts))
-            {
-                return default;
-            }
-
-            var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
-            var detector = JsonPatternDetector.GetOrCreate(
-                semanticModel, syntaxFacts, document.GetLanguageService<ISemanticFactsService>(), document.GetLanguageService<IVirtualCharService>());
-            if (!detector.IsDefinitelyJson(token, cancellationToken))
-            {
-                return default;
-            }
-
-            var tree = detector.TryParseJson(token, cancellationToken);
-            if (tree == null)
-            {
-                return default;
-            }
-
-            return GetMatchingBraces(tree, position);
-        }
-
-        private static BraceMatchingResult? GetMatchingBraces(JsonTree tree, int position)
-        {
-            var virtualChar = tree.Text.FirstOrNullable(vc => vc.Span.Contains(position));
-            if (virtualChar == null)
-            {
-                return null;
-            }
-
-            var ch = virtualChar.Value;
-            if (ch == '{' || ch == '[' || ch == '(' ||
-                ch == '}' || ch == ']' || ch == ')')
-            {
-                return FindBraceHighlights(tree, ch);
-            }
-
-            return null;
-        }
-
-        private static BraceMatchingResult? FindBraceHighlights(JsonTree tree, VirtualChar ch)
-        {
-            var node = FindObjectOrArrayNode(tree.Root, ch);
-            switch (node)
-            {
-                case JsonObjectNode obj: return Create(obj.OpenBraceToken, obj.CloseBraceToken);
-                case JsonArrayNode array: return Create(array.OpenBracketToken, array.CloseBracketToken);
-                case JsonConstructorNode cons: return Create(cons.OpenParenToken, cons.CloseParenToken);
-            }
-
-            return default;
-        }
-
-        private static BraceMatchingResult? Create(JsonToken open, JsonToken close)
-        {
-            if (open.IsMissing || close.IsMissing)
-            {
-                return default;
-            }
-
-            return new BraceMatchingResult(
-                JsonHelpers.GetSpan(open),
-                JsonHelpers.GetSpan(close));
-        }
-
-        private static JsonValueNode FindObjectOrArrayNode(JsonNode node, VirtualChar ch)
-        {
-            switch (node)
-            {
-                case JsonArrayNode array when Matches(array.OpenBracketToken, array.CloseBracketToken, ch):
-                    return array;
-
-                case JsonObjectNode obj when Matches(obj.OpenBraceToken, obj.CloseBraceToken, ch):
-                    return obj;
-
-                case JsonConstructorNode cons when Matches(cons.OpenParenToken, cons.CloseParenToken, ch):
-                    return cons;
-            }
-
-            foreach (var child in node)
-            {
-                if (child.IsNode)
-                {
-                    var result = FindObjectOrArrayNode(child.Node, ch);
-                    if (result != null)
-                    {
-                        return result;
-                    }
-                }
-            }
-
-            return null;
-        }
-
-        private static bool Matches(JsonToken openToken, JsonToken closeToken, VirtualChar ch)
-            => openToken.VirtualChars.Contains(ch) || closeToken.VirtualChars.Contains(ch);
-    }
-}

src/EditorFeatures/Core/Implementation/BraceMatching/CommonRegexBraceMatcher.cs

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.LanguageServices;
-using Microsoft.CodeAnalysis.RegularExpressions;
-using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.VirtualChars;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.Editor.Implementation.BraceMatching
-{
-    internal static class CommonRegexBraceMatcher
-    {
-        internal static async Task<BraceMatchingResult?> FindBracesAsync(
-            Document document, int position, CancellationToken cancellationToken)
-        {
-            var option = document.Project.Solution.Workspace.Options.GetOption(
-                RegularExpressionsOptions.HighlightRelatedRegexComponentsUnderCursor, document.Project.Language);
-            if (!option)
-            {
-                return default;
-            }
-
-            var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
-            var token = root.FindToken(position);
-
-            var syntaxFacts = document.GetLanguageService<ISyntaxFactsService>();
-            if (RegexPatternDetector.IsDefinitelyNotPattern(token, syntaxFacts))
-            {
-                return null;
-            }
-
-            var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
-            var detector = RegexPatternDetector.TryGetOrCreate(semanticModel, syntaxFacts, document.GetLanguageService<ISemanticFactsService>());
-            var tree = detector?.TryParseRegexPattern(token, document.GetLanguageService<IVirtualCharService>(), cancellationToken);
-
-            if (tree == null)
-            {
-                return null;
-            }
-
-            return GetMatchingBraces(tree, position);
-        }
-
-        private static BraceMatchingResult? GetMatchingBraces(RegexTree tree, int position)
-        {
-            var virtualChar = tree.Text.FirstOrNullable(vc => vc.Span.Contains(position));
-            if (virtualChar == null)
-            {
-                return null;
-            }
-
-            var ch = virtualChar.Value;
-            if (ch != '(' && ch != ')')
-            {
-                return null;
-            }
-
-            return FindBraceHighlights(tree, ch);
-        }
-
-        private static BraceMatchingResult? FindBraceHighlights(RegexTree tree, VirtualChar ch)
-        {
-            var node = FindGroupingNode(tree.Root, ch);
-            if (node == null)
-            {
-                return null;
-            }
-
-            if (node.OpenParenToken.IsMissing || node.CloseParenToken.IsMissing)
-            {
-                return null;
-            }
-
-            return new BraceMatchingResult(
-                node.OpenParenToken.VirtualChars[0].Span,
-                node.CloseParenToken.VirtualChars[0].Span);
-        }
-
-        private static RegexGroupingNode FindGroupingNode(RegexNode node, VirtualChar ch)
-        {
-            if (node is RegexGroupingNode grouping &&
-                (grouping.OpenParenToken.VirtualChars.Contains(ch) || grouping.CloseParenToken.VirtualChars.Contains(ch)))
-            {
-                return grouping;
-            }
-
-            foreach (var child in node)
-            {
-                if (child.IsNode)
-                {
-                    var result = FindGroupingNode(child.Node, ch);
-                    if (result != null)
-                    {
-                        return result;
-                    }
-                }
-            }
-
-            return null;
-        }
-    }
-}

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

-// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.Linq;
-using System.Reflection;
-using System.Runtime.CompilerServices;
-using System.Text.RegularExpressions;
-using System.Threading;
-using Microsoft.CodeAnalysis.LanguageServices;
-using Microsoft.CodeAnalysis.Shared.Extensions;
-using Microsoft.CodeAnalysis.VirtualChars;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.RegularExpressions
-{
-    /// <summary>
-    /// Helper class to detect regex pattern tokens in a document efficiently.
-    /// </summary>
-    internal class RegexPatternDetector
-    {
-        private const string _patternName = "pattern";
-
-        private static readonly ConditionalWeakTable<SemanticModel, RegexPatternDetector> _modelToDetector =
-            new ConditionalWeakTable<SemanticModel, RegexPatternDetector>();
-
-        private readonly SemanticModel _semanticModel;
-        private readonly ISyntaxFactsService _syntaxFacts;
-        private readonly ISemanticFactsService _semanticFacts;
-        private readonly INamedTypeSymbol _regexType;
-        private readonly HashSet<string> _methodNamesOfInterest;
-
-        /// <summary>
-        /// Helps match patterns of the form: language=regex,option1,option2,option3
-        /// 
-        /// All matching is case insensitive, with spaces allowed between the punctuation.
-        /// 'regex' or 'regexp' are both allowed.  Option values will be or'ed together
-        /// to produce final options value.  If an unknown option is encountered, processing
-        /// will stop with whatever value has accumulated so far.
-        /// 
-        /// Option names are the values from the <see cref="RegexOptions"/> enum.
-        /// </summary>
-        private static readonly Regex s_languageCommentDetector = 
-            new Regex(@"lang(uage)?\s*=\s*regex(p)?((\s*,\s*)(?<option>[a-zA-Z]+))*",
-                RegexOptions.ExplicitCapture | RegexOptions.IgnoreCase | RegexOptions.Compiled);
-
-        private static readonly Dictionary<string, RegexOptions> s_nameToOption =
-            typeof(RegexOptions).GetTypeInfo().DeclaredFields
-                .Where(f => f.FieldType == typeof(RegexOptions))
-                .ToDictionary(f => f.Name, f => (RegexOptions)f.GetValue(null), StringComparer.OrdinalIgnoreCase);
-
-        public RegexPatternDetector(
-            SemanticModel semanticModel, 
-            ISyntaxFactsService syntaxFacts,
-            ISemanticFactsService semanticFacts,
-            INamedTypeSymbol regexType, 
-            HashSet<string> methodNamesOfInterest)
-        {
-            _semanticModel = semanticModel;
-            _syntaxFacts = syntaxFacts;
-            _semanticFacts = semanticFacts;
-            _regexType = regexType;
-            _methodNamesOfInterest = methodNamesOfInterest;
-        }
-
-        public static RegexPatternDetector TryGetOrCreate(
-            SemanticModel semanticModel,
-            ISyntaxFactsService syntaxFacts,
-            ISemanticFactsService semanticFacts)
-        {
-            // Do a quick non-allocating check first.
-            if (_modelToDetector.TryGetValue(semanticModel, out var detector))
-            {
-                return detector;
-            }
-
-            return _modelToDetector.GetValue(
-                semanticModel, _ => TryCreate(semanticModel, syntaxFacts, semanticFacts));
-        }
-
-        private static RegexPatternDetector TryCreate(
-            SemanticModel semanticModel, 
-            ISyntaxFactsService syntaxFacts, 
-            ISemanticFactsService semanticFacts)
-        {
-            var regexType = semanticModel.Compilation.GetTypeByMetadataName(typeof(Regex).FullName);
-            if (regexType == null)
-            {
-                return null;
-            }
-
-            var methodNamesOfInterest = GetMethodNamesOfInterest(regexType, syntaxFacts);
-            return new RegexPatternDetector(
-                semanticModel, syntaxFacts, semanticFacts,
-                regexType, methodNamesOfInterest);
-        }
-
-        public static bool IsDefinitelyNotPattern(SyntaxToken token, ISyntaxFactsService syntaxFacts)
-        {
-            // We only support string literals passed in arguments to something.
-            // In the future we could support any string literal, as long as it has
-            // some marker (like a comment on it) stating it's a regex.
-            if (!syntaxFacts.IsStringLiteral(token))
-            {
-                return true;
-            }
-
-            if (!IsMethodOrConstructorArgument(token, syntaxFacts) && 
-                !HasRegexLanguageComment(token, syntaxFacts, out _))
-            {
-                return true;
-            }
-
-            return false;
-        }
-
-        private static bool HasRegexLanguageComment(
-            SyntaxToken token, ISyntaxFactsService syntaxFacts, out RegexOptions options)
-        {
-            if (HasRegexLanguageComment(token.GetPreviousToken().TrailingTrivia, syntaxFacts, out options))
-            {
-                return true;
-            }
-
-            for (var node = token.Parent; node != null; node = node.Parent)
-            {
-                if (HasRegexLanguageComment(node.GetLeadingTrivia(), syntaxFacts, out options))
-                {
-                    return true;
-                }
-            }
-
-            options = default;
-            return false;
-        }
-
-        private static bool HasRegexLanguageComment(
-            SyntaxTriviaList list, ISyntaxFactsService syntaxFacts, out RegexOptions options)
-        {
-            foreach (var trivia in list)
-            {
-                if (HasRegexLanguageComment(trivia, syntaxFacts, out options))
-                {
-                    return true;
-                }
-            }
-
-            options = default;
-            return false;
-        }
-
-        private static bool HasRegexLanguageComment(
-            SyntaxTrivia trivia, ISyntaxFactsService syntaxFacts, out RegexOptions options)
-        {
-            if (syntaxFacts.IsRegularComment(trivia))
-            {
-                var text = trivia.ToString();
-                var match = s_languageCommentDetector.Match(text);
-                if (match.Success)
-                {
-                    options = RegexOptions.None;
-
-                    var optionGroup = match.Groups["option"];
-                    foreach (Capture capture in optionGroup.Captures)
-                    {
-                        if (s_nameToOption.TryGetValue(capture.Value, out var specificOption))
-                        {
-                            options |= specificOption;
-                        }
-                        else
-                        {
-                            break;
-                        }
-                    }
-
-                    return true;
-                }
-            }
-
-            options = default;
-            return false;
-        }
-
-        private static bool IsMethodOrConstructorArgument(SyntaxToken token, ISyntaxFactsService syntaxFacts)
-            => syntaxFacts.IsLiteralExpression(token.Parent) &&
-               syntaxFacts.IsArgument(token.Parent.Parent);
-
-        private static HashSet<string> GetMethodNamesOfInterest(INamedTypeSymbol regexType, ISyntaxFactsService syntaxFacts)
-        {
-            var result = syntaxFacts.IsCaseSensitive
-                ? new HashSet<string>()
-                : new HashSet<string>(StringComparer.OrdinalIgnoreCase);
-
-            var methods = from method in regexType.GetMembers().OfType<IMethodSymbol>()
-                          where method.DeclaredAccessibility == Accessibility.Public
-                          where method.IsStatic
-                          where method.Parameters.Any(p => p.Name == _patternName)
-                          select method.Name;
-
-            result.AddRange(methods);
-
-            return result;
-        }
-
-        public bool IsRegexPattern(SyntaxToken token, CancellationToken cancellationToken, out RegexOptions options)
-        {
-            options = default;
-            if (IsDefinitelyNotPattern(token, _syntaxFacts))
-            {
-                return false;
-            }
-
-            if (HasRegexLanguageComment(token, _syntaxFacts, out options))
-            {
-                return true;
-            }
-
-            var stringLiteral = token;
-            var literalNode = stringLiteral.Parent;
-            var argumentNode = literalNode.Parent;
-            Debug.Assert(_syntaxFacts.IsArgument(argumentNode));
-
-            var argumentList = argumentNode.Parent;
-            var invocationOrCreation = argumentList.Parent;
-            if (_syntaxFacts.IsInvocationExpression(invocationOrCreation))
-            {
-                var invokedExpression = _syntaxFacts.GetExpressionOfInvocationExpression(invocationOrCreation);
-                var name = GetNameOfInvokedExpression(invokedExpression);
-                if (_methodNamesOfInterest.Contains(name))
-                {
-                    // Is a string argument to a method that looks like it could be a Regex method.  
-                    // Need to do deeper analysis
-                    var method = _semanticModel.GetSymbolInfo(invocationOrCreation, cancellationToken).GetAnySymbol();
-                    if (method != null &&
-                        method.DeclaredAccessibility == Accessibility.Public &&
-                        method.IsStatic &&
-                        _regexType.Equals(method.ContainingType))
-                    {
-                        return AnalyzeStringLiteral(
-                            stringLiteral, argumentNode, cancellationToken, out options);
-                    }
-                }
-            }
-            else if (_syntaxFacts.IsObjectCreationExpression(invocationOrCreation))
-            {
-                var typeNode = _syntaxFacts.GetObjectCreationType(invocationOrCreation);
-                var name = GetNameOfType(typeNode, _syntaxFacts);
-                if (name != null)
-                {
-                    if (_syntaxFacts.StringComparer.Compare(nameof(Regex), name) == 0)
-                    {
-                        var constructor = _semanticModel.GetSymbolInfo(invocationOrCreation, cancellationToken).GetAnySymbol();
-                        if (_regexType.Equals(constructor?.ContainingType))
-                        {
-                            // Argument to "new Regex".  Need to do deeper analysis
-                            return AnalyzeStringLiteral(
-                                stringLiteral, argumentNode, cancellationToken, out options);
-                        }
-                    }
-                }
-            }
-
-            return false;
-        }
-
-        public RegexTree TryParseRegexPattern(SyntaxToken token, IVirtualCharService virtualCharService, CancellationToken cancellationToken)
-        {
-            if (!this.IsRegexPattern(token, cancellationToken, out var options))
-            {
-                return null;
-            }
-
-            var chars = virtualCharService.TryConvertToVirtualChars(token);
-            if (chars.IsDefaultOrEmpty)
-            {
-                return null;
-            }
-
-            return RegexParser.TryParse(chars, options);
-        }
-
-        private bool AnalyzeStringLiteral(
-            SyntaxToken stringLiteral, SyntaxNode argumentNode, 
-            CancellationToken cancellationToken, out RegexOptions options)
-        {
-            options = default;
-
-            var parameter = _semanticFacts.FindParameterForArgument(_semanticModel, argumentNode, cancellationToken);
-            if (parameter?.Name != _patternName)
-            {
-                return false;
-            }
-
-            options = GetRegexOptions(argumentNode, cancellationToken);
-            return true;
-        }
-
-        private RegexOptions GetRegexOptions(SyntaxNode argumentNode, CancellationToken cancellationToken)
-        {
-            var argumentList = argumentNode.Parent;
-            var arguments = _syntaxFacts.GetArgumentsOfArgumentList(argumentList);
-            foreach (var siblingArg in arguments)
-            {
-                if (siblingArg != argumentNode)
-                {
-                    var expr = _syntaxFacts.GetExpressionOfArgument(siblingArg);
-                    if (expr != null)
-                    {
-                        var exprType = _semanticModel.GetTypeInfo(expr, cancellationToken);
-                        if (exprType.Type?.Name == nameof(RegexOptions))
-                        {
-                            var constVal = _semanticModel.GetConstantValue(expr, cancellationToken);
-                            if (constVal.HasValue)
-                            {
-                                return (RegexOptions)(int)constVal.Value;
-                            }
-                        }
-                    }
-                }
-            }
-
-            return RegexOptions.None;
-        }
-
-        private string GetNameOfType(SyntaxNode typeNode, ISyntaxFactsService syntaxFacts)
-        {
-            if (syntaxFacts.IsQualifiedName(typeNode))
-            {
-                return GetNameOfType(syntaxFacts.GetRightSideOfDot(typeNode), syntaxFacts);
-            }
-            else if (syntaxFacts.IsIdentifierName(typeNode))
-            {
-                return syntaxFacts.GetIdentifierOfSimpleName(typeNode).ValueText;
-            }
-
-            return null;
-        }
-
-        private string GetNameOfInvokedExpression(SyntaxNode invokedExpression)
-        {
-            if (_syntaxFacts.IsSimpleMemberAccessExpression(invokedExpression))
-            {
-                return _syntaxFacts.GetIdentifierOfSimpleName(_syntaxFacts.GetNameOfMemberAccessExpression(invokedExpression)).ValueText;
-            }
-            else if (_syntaxFacts.IsIdentifierName(invokedExpression))
-            {
-                return _syntaxFacts.GetIdentifierOfSimpleName(invokedExpression).ValueText;
-            }
-
-            return null;
-        }
-    }
-}

src/Workspaces/VisualBasic/Portable/Classification/SyntaxClassification/JsonPatternTokenClassifier.vb

-' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-Imports System.Collections.Immutable
-Imports System.Threading
-Imports Microsoft.CodeAnalysis.Classification
-Imports Microsoft.CodeAnalysis.VisualBasic.VirtualChars
-Imports Microsoft.CodeAnalysis.PooledObjects
-
-Namespace Microsoft.CodeAnalysis.VisualBasic.Classification.Classifiers
-    Friend Class JsonPatternTokenClassifier
-        Inherits AbstractSyntaxClassifier
-
-        Public Overrides ReadOnly Property SyntaxTokenKinds As ImmutableArray(Of Integer) = ImmutableArray.Create(Of Integer)(SyntaxKind.StringLiteralToken)
-
-        Public Overrides Sub AddClassifications(workspace As Workspace, token As SyntaxToken, semanticModel As SemanticModel, result As ArrayBuilder(Of ClassifiedSpan), cancellationToken As CancellationToken)
-            Debug.Assert(token.Kind() = SyntaxKind.StringLiteralToken)
-            CommonJsonPatternTokenClassifier.AddClassifications(
-                workspace, token, semanticModel, result,
-                VisualBasicSyntaxFactsService.Instance,
-                VisualBasicSemanticFactsService.Instance,
-                VisualBasicVirtualCharService.Instance,
-                cancellationToken)
-        End Sub
-    End Class
-End Namespace

src/Workspaces/VisualBasic/Portable/Classification/SyntaxClassification/RegexPatternTokenClassifier.vb

-' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-Imports System.Collections.Immutable
-Imports System.Threading
-Imports Microsoft.CodeAnalysis.Classification
-Imports Microsoft.CodeAnalysis.PooledObjects
-Imports Microsoft.CodeAnalysis.VisualBasic.VirtualChars
-
-Namespace Microsoft.CodeAnalysis.VisualBasic.Classification.Classifiers
-    Friend Class RegexPatternTokenClassifier
-        Inherits AbstractSyntaxClassifier
-
-        Public Overrides ReadOnly Property SyntaxTokenKinds As ImmutableArray(Of Integer) = ImmutableArray.Create(Of Integer)(SyntaxKind.StringLiteralToken)
-
-        Public Overrides Sub AddClassifications(workspace As Workspace, token As SyntaxToken, semanticModel As SemanticModel, result As ArrayBuilder(Of ClassifiedSpan), cancellationToken As CancellationToken)
-            Debug.Assert(token.Kind() = SyntaxKind.StringLiteralToken)
-            CommonRegexPatternTokenClassifier.AddClassifications(
-                workspace, token, semanticModel, result,
-                VisualBasicSyntaxFactsService.Instance,
-                VisualBasicSemanticFactsService.Instance,
-                VisualBasicVirtualCharService.Instance,
-                cancellationToken)
-        End Sub
-    End Class
-End Namespace