Improve handling of built-in identifiers.

dart/lib/compiler/implementation/scanner/token.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 const int EOF_TOKEN = 0;
 
 const int KEYWORD_TOKEN = $k;
 const int IDENTIFIER_TOKEN = $a;
 const int DOUBLE_TOKEN = $d;
 const int INT_TOKEN = $i;
@@ skipping 106 matching lines @@
   /**
    * The kind enum of this token as determined by its [info].
    */
   int get kind => info.kind;
 
   /**
    * The precedence level for this token.
    */
   int get precedence => info.precedence;
 
-  bool isIdentifier() {
-    if (kind === IDENTIFIER_TOKEN) return true;
-    if (kind === KEYWORD_TOKEN) return value.isPseudo;
-    return false;
-  }
+  bool isIdentifier() => kind === IDENTIFIER_TOKEN;
 
   /**
    * Returns a textual representation of this token to be used for debugging
    * purposes. The resulting string might contain information about the
    * structure of the token, for example 'StringToken(foo)' for the identifier
    * token 'foo'. Use [slowToString] for the text actually parsed by the token.
    */
   String toString() => info.value.toString();
 
   /**
@@ skipping 10 matching lines @@
 /**
  * A keyword token.
  */
 class KeywordToken extends Token {
   final Keyword value;
   String get stringValue => value.syntax;
 
   KeywordToken(Keyword value, int charOffset)
     : this.value = value, super(value.info, charOffset);
 
+  bool isIdentifier() => value.isPseudo || value.isBuiltIn;
+
   String toString() => value.syntax;
 }
 
 /**
  * A String-valued token.
  */
 class StringToken extends Token {
   final SourceString value;
   String get stringValue => value.stringValue;
 
@@ skipping 328 matching lines @@
 
 const PrecedenceInfo HEXADECIMAL_INFO =
   const PrecedenceInfo(const SourceString('hexadecimal'), 0, HEXADECIMAL_TOKEN);
 
 const PrecedenceInfo COMMENT_INFO =
   const PrecedenceInfo(const SourceString('comment'), 0, COMMENT_TOKEN);
 
 // For reporting lexical errors.
 const PrecedenceInfo ERROR_INFO =
   const PrecedenceInfo(const SourceString('?'), 0, UNKNOWN_TOKEN);