Regexp: Fix rightContext in the lastMatchInfoOverride

Regexp: Fix rightContext in the lastMatchInfoOverride
case.
Committed: http://code.google.com/p/v8/source/detail?r=11285

[Michael Starzinger, 2012-04-12 12:10:28]

LGTM (with a nit).

http://codereview.chromium.org/10068010/diff/1/src/regexp.js
File src/regexp.js (right):

http://codereview.chromium.org/10068010/diff/1/src/regexp.js#newcode346
src/regexp.js:346: var subject, pattern;
The "pattern" variable could be moved into the else block.

[Lasse Reichstein Nielsen, 2012-04-13 06:59:52]

http://codereview.chromium.org/10068010/diff/1/src/regexp.js
File src/regexp.js (right):

http://codereview.chromium.org/10068010/diff/1/src/regexp.js#newcode353
src/regexp.js:353: pattern = override[override.length - 3];
I don't think this is correct in all cases.

The override has the same format as the parameters to a function argument of
String.prototype.replace. I.e., it's 
[match, captures*, match-position, subject].

So 'pattern' should probably be called 'match', and it should be read as
override[0], not override[override.length - 3], in the cases where there are
captures.

You might want to consider making macros like

 macro OVERRIDE_MATCH(override) = ((override)[0]);
 macro OVERRIDE_POS(override) = ((override)[(override).length - 2]);
 macro OVERRIDE_SUBJECT(override) = ((override)[(override).length - 1]);
 macro OVERRIDE_CAPTURE(override, index) = ((override)[(index) + 1]);

(if for nothing else, it's documentation :)