On Jul 17, 5:40 pm, Paul Rubin <http://phr...@nospam.invalid> wrote: > Zac Burns <zac...@gmail.com> writes: > > An example use case for this would be for something like a large table > > of regular expressions that would be iterated over trying to match in > > some string. If some regular expressions are more statistically more > > successful then the iteration will generally be short. > > Generally if you are matching against a bunch of regexps, they will > tend to match overlapping sets, so you want to control precisely what > order they are tested in. Having stuff bubble around based on hit > counts doesn't sound good.
As a corrollary, if you happen to be matching non-overlapping sets, then it is a red flag that there could be some other (better) way to dispatch than a linear regexp search. For instance, if all your regexps start with a different keyword, then you should dispatch on that keyword using a dictionary. A regexp can be used after dispatching to extract parameters if necessary. It's possible to have disjoint regexps without a simple dispatch criterion, but I'd guess that's less common. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
