#Boost xpressive code#

CTR can be implemented through meta-programming and/or code generation.Īs for specific implementations - there are many RTR, but not so numerous CTR. This is particularly annoying because a main force of Xpressive is the ability to construct complex regexp from simplier one, which can be quickly become a nightmare if using pcre or equivalent.ut if it comes with such a performance cost, the benefit looks annihilated.tw, is the library still maintained according to boost changelog, no. Primary dependencies for conversion assert from from Another advantage is compile-time syntax checking. RTR are 'compiled' and interpreted by some kind of universal finite state machine(universal means its kind of interpreter which scheme is given at run-time, 'compiled' in some internal data structure - when you pass regex string, then interpreted at run-time).īut CTR is 'compiled' at compile-time and are specific for particular regex, so you can't use them, when regex is given at run-time(applications like text editors, file/internet search engines).īut they are a priori more efficient(theoretically however) as customized in compile-time finite state machine will be efficient, than interpreter with table-preset scheme of this machine(some similar cases are reflection field access vs compile-time access, or specialized function optimized for some fixed parameter as pointed out there). No single intervention will suit everyone: writing is just one tool and some may balk at the idea of setting out their. They are OK when regular expression is determined at run-time, unlike CTR. Expressive writing can help us to make this mental transformation in private. This is an online code browser that allows you to browse C/C++ code just like in your IDE, with semantic highlighting and contextual tooltips that show you the. Run-time regex are more known and popular(most language core-libraries implementations), i suppose due to historical reasons. I would try to supplement other people answers by get deeper into topic of compile-time regular expressions(CTR) vs run-time(dynamic) regular expressions(RTR) in a more theoretical way(this topic is implied by OP question indirectly IMHO).