Update partial parser and scanner to be able to skip expressions like "new Map<S, T>()".

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

 // Copyright (c) 2012, 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.
 
 interface Scanner {
   Token tokenize();
 }
 
 /**
  * Common base class for a Dart scanner.
@@ skipping 15 matching lines @@
   abstract Token previousToken();
   abstract void beginToken();
   abstract void addToCharOffset(int offset);
   abstract int get charOffset();
   abstract int get byteOffset();
   abstract void appendBeginGroup(PrecedenceInfo info, String value);
   abstract int appendEndGroup(PrecedenceInfo info, String value, int openKind);
   abstract void appendGt(PrecedenceInfo info, String value);
   abstract void appendGtGt(PrecedenceInfo info, String value);
   abstract void appendGtGtGt(PrecedenceInfo info, String value);
+
+  /**
+   * We call this method to discard '<' from the "grouping" stack
+   * (maintained by subclasses). That we don't create groups for stuff
+   * like "a = b < c, d = e > f" is used by
+   * [PartialParser.skipExpression].
+   */

[Lasse Reichstein Nielsen, 2012/06/15 13:59:14]

So you call this when you recognize something that can't possibly be part of a
type parameter/type argument?

[ahe, 2012/06/19 11:02:42]

Done.

   abstract void discardOpenLt();
 
   // TODO(ahe): Move this class to implementation.
 
   Token tokenize() {
     int next = advance();
     while (next !== $EOF) {
       next = bigSwitch(next);
     }
     appendEofToken();
@@ skipping 90 matching lines @@
       return advance();
     }
 
     if (next === $COLON) {
       appendPrecedenceToken(COLON_INFO);
       return advance();
     }
 
     if (next === $SEMICOLON) {
       appendPrecedenceToken(SEMICOLON_INFO);
+      // Type parameters and arguments cannot contain semicolon.
       discardOpenLt();
       return advance();
     }
 
     if (next === $QUESTION) {
       appendPrecedenceToken(QUESTION_INFO);
       return advance();
     }
 
     if (next === $CLOSE_SQUARE_BRACKET) {
@@ skipping 178 matching lines @@
     next = advance();
     if (next === $EQ) {
       return select($EQ, BANG_EQ_EQ_INFO, BANG_EQ_INFO);
     }
     appendPrecedenceToken(BANG_INFO);
     return next;
   }
 
   int tokenizeEquals(int next) {
     // = == ===
+
+    // Type parameters and arguments cannot contain any token that
+    // starts with '='.
+    discardOpenLt();
+
     next = advance();
     if (next === $EQ) {
       return select($EQ, EQ_EQ_EQ_INFO, EQ_EQ_INFO);
     } else if (next === $GT) {
       appendPrecedenceToken(FUNCTION_INFO);
       return advance();
     }
     appendPrecedenceToken(EQ_INFO);
     return next;
   }
 
   int tokenizeGreaterThan(int next) {
     // > >= >> >>= >>> >>>=

[Lasse Reichstein Nielsen, 2012/06/15 13:59:14]

When type names can be expressions (reified types), will we be able to correctly
parse
  Set<int>==T
? And what will be correct?!? Tokenization? is! fun, :)

[ahe, 2012/06/19 11:02:42]

Yay! More fun to be had in the future. :-)

     next = advance();
     if ($EQ === next) {
       appendPrecedenceToken(GT_EQ_INFO);
       return advance();
     } else if ($GT === next) {
       next = advance();
       if ($EQ === next) {
         appendPrecedenceToken(GT_GT_EQ_INFO);
         return advance();
       } else if ($GT === next) {
@@ skipping 394 matching lines @@
                                       charOffset);
   }
 }
 
 class MalformedInputException {
   final String message;
   final position;
   MalformedInputException(this.message, this.position);
   toString() => message;
 }