Stub implementation of patch invariants for the patch refactoring.

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 BAD_INPUT_TOKEN = $X;
 const int DOUBLE_TOKEN = $d;
@@ skipping 66 matching lines @@
 const int COMMENT_TOKEN = AS_TOKEN + 1;
 const int GT_GT_GT_TOKEN = COMMENT_TOKEN + 1;
 const int STRING_INTERPOLATION_IDENTIFIER_TOKEN = COMMENT_TOKEN + 1;
 
 // TODO(ahe): Get rid of this.
 const int UNKNOWN_TOKEN = 1024;
 
 /**
  * A token that doubles as a linked list.
  */
-class Token {
+class Token implements Spanable {
   /**
    * The precedence info for this token. [info] determines the kind and the
    * precedence level of this token.
    */
   final PrecedenceInfo info;
 
   /**
    * The character offset of the start of this token within the source text.
    */
   final int charOffset;
@@ skipping 405 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);