Implement 'as' operator.

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.
 
 final int EOF_TOKEN = 0;
 
 final int KEYWORD_TOKEN = $k;
 final int IDENTIFIER_TOKEN = $a;
 final int DOUBLE_TOKEN = $d;
 final int INT_TOKEN = $i;
@@ skipping 53 matching lines @@
 final int PLUS_PLUS_TOKEN = STAR_EQ_TOKEN + 1;
 final int PLUS_EQ_TOKEN = PLUS_PLUS_TOKEN + 1;
 final int MINUS_MINUS_TOKEN = PLUS_EQ_TOKEN + 1;
 final int MINUS_EQ_TOKEN = MINUS_MINUS_TOKEN + 1;
 final int TILDE_SLASH_EQ_TOKEN = MINUS_EQ_TOKEN + 1;
 final int TILDE_SLASH_TOKEN = TILDE_SLASH_EQ_TOKEN + 1;
 final int PERCENT_EQ_TOKEN = TILDE_SLASH_TOKEN + 1;
 final int GT_GT_TOKEN = PERCENT_EQ_TOKEN + 1;
 final int CARET_EQ_TOKEN = GT_GT_TOKEN + 1;
 final int IS_TOKEN = CARET_EQ_TOKEN + 1;
-final int COMMENT_TOKEN = IS_TOKEN + 1;
+final int AS_TOKEN = IS_TOKEN + 1;
+final int COMMENT_TOKEN = AS_TOKEN + 1;
 final int GT_GT_GT_TOKEN = COMMENT_TOKEN + 1;
 final int STRING_INTERPOLATION_IDENTIFIER_TOKEN = COMMENT_TOKEN + 1;
 
 // TODO(ahe): Get rid of this.
 final int UNKNOWN_TOKEN = 1024;
 
 /**
  * A token that doubles as a linked list.
  */
 class Token {
@@ skipping 314 matching lines @@
 final PrecedenceInfo EQ_EQ_INFO =
   const PrecedenceInfo(const SourceString('=='), 9, EQ_EQ_TOKEN);
 
 // Relational operators.
 final PrecedenceInfo GT_EQ_INFO =
   const PrecedenceInfo(const SourceString('>='), 10, GT_EQ_TOKEN);
 final PrecedenceInfo GT_INFO =
   const PrecedenceInfo(const SourceString('>'), 10, GT_TOKEN);
 final PrecedenceInfo IS_INFO =
   const PrecedenceInfo(const SourceString('is'), 10, IS_TOKEN);
+final PrecedenceInfo AS_INFO =
+  const PrecedenceInfo(const SourceString('as'), 10, AS_TOKEN);
 final PrecedenceInfo LT_EQ_INFO =
   const PrecedenceInfo(const SourceString('<='), 10, LT_EQ_TOKEN);
 final PrecedenceInfo LT_INFO =
   const PrecedenceInfo(const SourceString('<'), 10, LT_TOKEN);
 
 // Shift operators.
 final PrecedenceInfo GT_GT_GT_INFO =
   const PrecedenceInfo(const SourceString('>>>'), 11, GT_GT_GT_TOKEN);
 final PrecedenceInfo GT_GT_INFO =
   const PrecedenceInfo(const SourceString('>>'), 11, GT_GT_TOKEN);
@@ skipping 69 matching lines @@
 
 final PrecedenceInfo HEXADECIMAL_INFO =
   const PrecedenceInfo(const SourceString('hexadecimal'), 0, HEXADECIMAL_TOKEN);
 
 final PrecedenceInfo COMMENT_INFO =
   const PrecedenceInfo(const SourceString('comment'), 0, COMMENT_TOKEN);
 
 // For reporting lexical errors.
 final PrecedenceInfo ERROR_INFO =
   const PrecedenceInfo(const SourceString('?'), 0, UNKNOWN_TOKEN);