By looking at the benchmarks, it is interesting to see how much an advantage have non-backtracking engines versus the default Java one. It is also interesting that most of the regular expressions I happen to write are not backtracking, so it’s likely I’m paying a ticket every time for a feature I’m not going to see.

It would be interesting if the default Java class the implements regular expressions would detect whether backtracking is actually used in the regular expression when it is compiled and decide whether the full blown engine is really necessary or a lightweight one would be enough.