Expect 'extends' in type parameters declaration and recover, issue 341

Expect 'extends' in type parameters declaration and recover, issue 341
http://code.google.com/p/dart/issues/detail?id=341


R=zundel@google.com
BUG=
TEST=

Committed: https://code.google.com/p/dart/source/detail?r=1668

[zundel, 2011-11-16 20:05:07]

I'm not sure how far we should take parser robustness in just this one change
without coming up with a good overall strategy, but I am wary of the current
logic of consuming all tokens with next() - I think we might want to bail out of
that loop sooner in more cases.

http://codereview.chromium.org/8576007/diff/1/compiler/java/com/google/dart/c...
File compiler/java/com/google/dart/compiler/parser/DartParser.java (right):

http://codereview.chromium.org/8576007/diff/1/compiler/java/com/google/dart/c...
compiler/java/com/google/dart/compiler/parser/DartParser.java:461: next();
this could skip way too far.  You might also stop at a } or class keyword.

http://codereview.chromium.org/8576007/diff/1/compiler/java/com/google/dart/c...
compiler/java/com/google/dart/compiler/parser/DartParser.java:465: // done
unnecessary comment

http://codereview.chromium.org/8576007/diff/1/compiler/javatests/com/google/d...
File compiler/javatests/com/google/dart/compiler/parser/NegativeParserTest.java
(right):

http://codereview.chromium.org/8576007/diff/1/compiler/javatests/com/google/d...
compiler/javatests/com/google/dart/compiler/parser/NegativeParserTest.java:248:
}
there are other cases you could add, like leaving off the > at the end of a type
parameter.  This would be likely in the case of a user entering in code in the
IDE.

[zundel, 2011-11-18 18:04:33]

LGTM other than some nits.

http://codereview.chromium.org/8576007/diff/5001/compiler/java/com/google/dar...
File compiler/java/com/google/dart/compiler/parser/DartParser.java (right):

http://codereview.chromium.org/8576007/diff/5001/compiler/java/com/google/dar...
compiler/java/com/google/dart/compiler/parser/DartParser.java:468: // XXX
spurious comment

http://codereview.chromium.org/8576007/diff/5001/compiler/java/com/google/dar...
compiler/java/com/google/dart/compiler/parser/DartParser.java:490:
reportErrorWithoutAdvancing(ParserErrorCode.EXPECTED_EXTENDS);
Using reportErrorWithoutAdvancing() and then calling next()  seems a slight bit
more awkward than;

next();
reportError(ErrorCode)

which I think does the same thing.

http://codereview.chromium.org/8576007/diff/5001/compiler/java/com/google/dar...
File compiler/java/com/google/dart/compiler/parser/ParserErrorCode.java (right):

http://codereview.chromium.org/8576007/diff/5001/compiler/java/com/google/dar...
compiler/java/com/google/dart/compiler/parser/ParserErrorCode.java:66:
SKIPPED_SOURCE("This part of source was not parsed because of previous parsing
problem"),
(Missing 'the' and 'a')
This part of the source ... of a previous parsing...

[fabiomfv, 2011-11-18 18:53:22]

http://codereview.chromium.org/8576007/diff/1/compiler/java/com/google/dart/c...
File compiler/java/com/google/dart/compiler/parser/DartParser.java (right):

http://codereview.chromium.org/8576007/diff/1/compiler/java/com/google/dart/c...
compiler/java/com/google/dart/compiler/parser/DartParser.java:461: next();
though we want (and need) error recovery, we probably need a systematic
approach. Also, the 'follow-set' for 'extends' includes more than comma, > .