* Add support for positive lookahead assertions and negative...

* Add support for positive lookahead assertions and negative
  lookahead assertions.
* Fix sense of CheckChar and CheckNotChar to match CheckCharLT
  in bytecode assembler.  Also rename them from Char to Character.
* Mark unexpected pass in Mozilla tests (we can cope with 500
  parentheses).
* Mark unexpected hang in Mozilla tests (exponential regexp,
  JSCRE bails out).
* Support negative character classes (yes, the parser still
  generates them).

Committed: http://code.google.com/p/v8/source/detail?r=804

[Lasse Reichstein, 2008-11-20 10:32:11]

LGTM

http://codereview.chromium.org/11319/diff/1/6
File src/assembler-re2k.cc (right):

http://codereview.chromium.org/11319/diff/1/6#newcode85
Line 85: void Re2kAssembler::SetCurrentPositionFromRegister(int index) {
You have "Write..To" but "Set..From". Wouldn't it be more nicely symmetric if it
was "Read...From"?

http://codereview.chromium.org/11319/diff/1/11
File src/jsregexp.cc (right):

http://codereview.chromium.org/11319/diff/1/11#newcode1701
Line 1701: int stack_pointer_register = compiler->AllocateRegister();
You never free a register again. 
Would it be possible to free registers, and perhaps reuse them?

[Erik Corry, 2008-11-20 11:37:34]

http://codereview.chromium.org/11319/diff/1/6
File src/assembler-re2k.cc (right):

http://codereview.chromium.org/11319/diff/1/6#newcode85
Line 85: void Re2kAssembler::SetCurrentPositionFromRegister(int index) {
On 2008/11/20 10:32:11, Lasse Reichstein wrote:
> You have "Write..To" but "Set..From". Wouldn't it be more nicely symmetric if
it
> was "Read...From"?
> 

Done

http://codereview.chromium.org/11319/diff/1/11
File src/jsregexp.cc (right):

http://codereview.chromium.org/11319/diff/1/11#newcode1701
Line 1701: int stack_pointer_register = compiler->AllocateRegister();
On 2008/11/20 10:32:11, Lasse Reichstein wrote:
> You never free a register again. 
> Would it be possible to free registers, and perhaps reuse them?

We could free them if we checked for nested expressions.  I don't think it's
worth worrying about at this stage.