Re: [boost] [regex] specify parenthesis

From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2007-05-01 10:16:59

Lorenzo wrote:
> is there a way to specify open and closed parenthesis with a
> regular expression syntax?  For instance, if I'd want to specify a
> single regular expression that matches both (foo) and [foo] and {foo}?

Lorenzo,

Matching parentheses to arbitrary depth is, like matching palindromes, 
a textbook example of something that cannot be done with a regular 
language and instead needs a context-free language.  Google for 
"chomsky hierarchy palindrome" for some background material.  Of 
course, it's possible that some regexp library somewhere has a hack to 
add this functionality.  But fundamentally, you need a more 
sophisticated parser.

Phil.