On 7/21/2010 2:39 PM, Pavol Supa wrote:
Hi,
I need to match a hex-written byte array, optionally separated with spaces. So i tried:
boost::xpressive::sregex r = * ( * blank >> repeat<2,2> (xdigit)); smatch match; regex_match (input, match, r);
when i use input of approx. 150 hex pairs, i get an exception "Regex stack space exhausted" (i use default stack size by Visual studio 2008)
This pattern looks quite simple, so I'd like to know, if there is some fundamental problem with this expressions.
Yes. See http://www.boost.org/doc/libs/1_43_0/doc/html/xpressive/user_s_guide.html#bo... Not only will this pattern tear through stack, it'll run very slowly. Try this instead: * ( keep(*blank) >> repeat<2,2> (xdigit))
I know i can enlarge the stack manually, but i expect the input to be cca 10kB long, depending on user input, so i consider it not being a good solution.
-- Eric Niebler BoostPro Computing http://www.boostpro.com