On: Google Code Search team says Goodbye

[bad_user]

It depends on what you mean by regex. Modern engines go beyond the capabilities of regular expression grammars, describing things that are not possible with a finite-state machine.

And for example, the regex engine from Perl 5.10 and up has had support for recursive patterns. See the faq: http://perldoc.perl.org/perlfaq6.html#Can-I-use-Perl-regular...

And once you have recursion support, you can parse context-free languages.