Add symbol keyword

Author: JsonFreeman

src/compiler/checker.ts

@@ -9751,6 +9751,7 @@ module ts {
                 case SyntaxKind.NumberKeyword:
                 case SyntaxKind.StringKeyword:
                 case SyntaxKind.BooleanKeyword:
+                case SyntaxKind.SymbolKeyword:
                     return true;
                 case SyntaxKind.VoidKeyword:
                     return node.parent.kind !== SyntaxKind.VoidExpression;
@@ -10529,7 +10530,7 @@ module ts {
                 return grammarErrorOnNode(parameter.name, Diagnostics.An_index_signature_parameter_must_have_a_type_annotation);
             }
             if (parameter.type.kind !== SyntaxKind.StringKeyword && parameter.type.kind !== SyntaxKind.NumberKeyword) {
-                if (isESSymbolTypeNode(parameter.type)) {
+                if (parameter.type.kind === SyntaxKind.SymbolKeyword) {
                     if (languageVersion < ScriptTarget.ES6) {
                         return grammarErrorOnNode(parameter.type, Diagnostics.Symbol_indexers_are_only_available_when_targeting_ECMAScript_6_and_higher);
                     }

src/compiler/emitter.ts

@@ -579,6 +579,7 @@ module ts {
                 case SyntaxKind.StringKeyword:
                 case SyntaxKind.NumberKeyword:
                 case SyntaxKind.BooleanKeyword:
+                case SyntaxKind.SymbolKeyword:
                 case SyntaxKind.VoidKeyword:
                 case SyntaxKind.StringLiteral:
                     return writeTextOfNode(currentSourceFile, type);

src/compiler/parser.ts

@@ -2515,6 +2515,7 @@ module ts {
                 case SyntaxKind.StringKeyword:
                 case SyntaxKind.NumberKeyword:
                 case SyntaxKind.BooleanKeyword:
+                case SyntaxKind.SymbolKeyword:
                     // If these are followed by a dot, then parse these out as a dotted type reference instead.
                     var node = tryParse(parseKeywordAndNoDot);
                     return node || parseTypeReference();
@@ -2539,6 +2540,7 @@ module ts {
                 case SyntaxKind.StringKeyword:
                 case SyntaxKind.NumberKeyword:
                 case SyntaxKind.BooleanKeyword:
+                case SyntaxKind.SymbolKeyword:
                 case SyntaxKind.VoidKeyword:
                 case SyntaxKind.TypeOfKeyword:
                 case SyntaxKind.OpenBraceToken:

src/compiler/scanner.ts

@@ -82,6 +82,7 @@ module ts {
         "string": SyntaxKind.StringKeyword,
         "super": SyntaxKind.SuperKeyword,
         "switch": SyntaxKind.SwitchKeyword,
+        "symbol": SyntaxKind.SymbolKeyword,
         "this": SyntaxKind.ThisKeyword,
         "throw": SyntaxKind.ThrowKeyword,
         "true": SyntaxKind.TrueKeyword,

src/compiler/types.ts

@@ -140,6 +140,7 @@ module ts {
         NumberKeyword,
         SetKeyword,
         StringKeyword,
+        SymbolKeyword,
         TypeKeyword,
 
         // Parse tree nodes

src/compiler/utilities.ts

@@ -852,12 +852,6 @@ module ts {
         return node.kind === SyntaxKind.PropertyAccessExpression && isESSymbolIdentifier((<PropertyAccessExpression>node).expression);
     }
 
-    export function isESSymbolTypeNode(node: Node): boolean {
-        return node.kind === SyntaxKind.TypeReference &&
-            (<TypeReferenceNode>node).typeArguments === undefined &&
-            isESSymbolIdentifier((<TypeReferenceNode>node).typeName);
-    }
-
     /**
      * Includes the word "Symbol" with unicode escapes
      */

src/services/formatting/tokenRange.ts

@@ -134,7 +134,7 @@ module ts.formatting {
             static UnaryPredecrementExpressions = TokenRange.FromTokens([SyntaxKind.Identifier, SyntaxKind.OpenParenToken, SyntaxKind.ThisKeyword, SyntaxKind.NewKeyword]);
             static UnaryPostdecrementExpressions = TokenRange.FromTokens([SyntaxKind.Identifier, SyntaxKind.CloseParenToken, SyntaxKind.CloseBracketToken, SyntaxKind.NewKeyword]);
             static Comments = TokenRange.FromTokens([SyntaxKind.SingleLineCommentTrivia, SyntaxKind.MultiLineCommentTrivia]);
-            static TypeNames = TokenRange.FromTokens([SyntaxKind.Identifier, SyntaxKind.NumberKeyword, SyntaxKind.StringKeyword, SyntaxKind.BooleanKeyword, SyntaxKind.VoidKeyword, SyntaxKind.AnyKeyword]);
+            static TypeNames = TokenRange.FromTokens([SyntaxKind.Identifier, SyntaxKind.NumberKeyword, SyntaxKind.StringKeyword, SyntaxKind.BooleanKeyword, SyntaxKind.SymbolKeyword, SyntaxKind.VoidKeyword, SyntaxKind.AnyKeyword]);
         }
     }
 }

src/services/services.ts

@@ -5754,7 +5754,8 @@ module ts {
                     else if (token === SyntaxKind.AnyKeyword ||
                              token === SyntaxKind.StringKeyword ||
                              token === SyntaxKind.NumberKeyword ||
-                             token === SyntaxKind.BooleanKeyword) {
+                             token === SyntaxKind.BooleanKeyword ||
+                             token === SyntaxKind.SymbolKeyword) {
                              if (angleBracketStack > 0 && !classifyKeywordsInGenerics) {
                                  // If it looks like we're could be in something generic, don't classify this 
                                  // as a keyword.  We may just get overwritten by the syntactic classifier,