3 ms·
What sort of Regex are they using? The garden variety can be compiled to DFAs (O(n)) which a modern computer should have no issues handling. Further optimizatio
by sansnomme 7y ago
What sort of Regex are they using? The garden variety can be compiled to DFAs (O(n)) which a modern computer should have no issues handling. Further optimizations
- rcthompson 7y agoI believe Emacs has its own regular expression syntax that doesn't correspond exactly to either POSIX regexes, PCRE, or any other common regex variant. (Presumably because none of them existed yet when Emacs implemented regexes?)
- sedachv 7y agoHere is a good example: http://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/emacs-lisp/lisp-mode.el#n430 http://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/emacs-l... DFAs for regular expressions use exponential memory for regular expression size (also exponential time to compile them to DFAs). Try that for the regular expressions in the link above. There is no way to make regular expressions fast.