Implement parsing and resolving of type-variables.

frog/leg/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 122 matching lines @@
 
   /** Gives a [SourceString] that is not including the [initial] first and
    * [terminal] last characters. This is only intended to be used to remove
    * quotes from string literals (including an initial '@' for raw strings).
    */
   SourceString copyWithoutQuotes(int initial, int terminal);
 
   String get stringValue();
 
   String slowToString();
+
   bool isEmpty();
 }
 
 class StringWrapper implements SourceString {
   final String stringValue;
 
   const StringWrapper(String this.stringValue);
 
   int hashCode() => stringValue.hashCode();
 
@@ skipping 272 matching lines @@
 final PrecedenceInfo STRING_INTERPOLATION_INFO =
   const PrecedenceInfo(const SourceString('\${'), 0,
                        STRING_INTERPOLATION_TOKEN);
 
 final PrecedenceInfo HEXADECIMAL_INFO =
   const PrecedenceInfo(const SourceString('hexadecimal'), 0, HEXADECIMAL_TOKEN);
 
 // For reporting lexical errors.
 final PrecedenceInfo ERROR_INFO =
   const PrecedenceInfo(const SourceString('?'), 0, UNKNOWN_TOKEN);