For Photon, a micro framework for Mongrel2, we use regex. Even with 100's or 1000's of routes, you cannot even see the cost of preg_match when benchmarking because the regex are organized in a tree following the URI structure like Django. It means that most of the time, a view is found within 2 to 3 preg_match calls.

This - regex is slow to match anchored strings on a 120 character long URI - is a myth.

For matching? Because PCRE/PHP_PCRE already caches the compiled versions of regexes, so there's little to no perf hit there.

For most requests, there is no regex matching done, because it also caches the resolved route for a given URI :)