I'm working on extending original GNU Emacs regexp. The following extension are available currently.
- Lookaround
- Positive Lookahead
\(?=...\) - Negative Lookahead
\(?!...\) - Positive Lookbehind
\(?<=...\) - Negative Lookbehind
\(?<!...\\)
- Positive Lookahead
Source Code
There is a bazaar branch of GNU Emacs 23.1:
http://cx4a.org/repo/emacs.bzr/regexp/
You can checkout with bzr command like:
$ bzr branch http://cx4a.org/repo/emacs.bzr/regexp/
And you can compile it as usual.
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