I'll add two notes to this: * Finite automata based regex engines don't necessarily have to be slower than backtracking engines like PCRE. Go's regexp is in pr

I'll add two notes to this: * Finite automata based regex engines don't necessarily have to be slower than backtracking engines like PCRE. Go's regexp is in practice slower in a lot of cases, but this is more a property of its implementation than its concept. See: https://github.com/BurntSushi/rebar?tab=readme-ov-file#summary-of-search-time-benchmarks https://github.com/BurntSushi/rebar?tab=readme-ov-file#summa... --- Given "sufficient" implementation effort (~several person years of development work), backtrackers and finite automata engines can both perform very well, with one beating the other in some cases but not in others. It depends. * Fun fact is that if you're iterating over all matches in a haystack (e.g., Go's `FindAll` routines), then you're susceptible to O(m * n^2) search time. This applies to all regex engines that implement some kind of leftmost match priority. See https://github.com/BurntSushi/rebar?tab=readme-ov-file#quadratic https://github.com/BurntSushi/rebar?tab=readme-ov-file#quadr... for a more detailed elaboration on this point.