But I'm not sure how far they got. And most of the links on that page are dead. :-(
And yeah, UTS#18 actually used to have a level 3 (custom tailoring), but they removed it.
I'm content with level 1 support. The regex crate is just about there and that actually makes it have better Unicode support than the vast majority of regex engines. :-)
Not sure about backtrackers, but I know ICgrep attempted quite a bit of level 2: http://international-characters.com/icgrep
But I'm not sure how far they got. And most of the links on that page are dead. :-(
And yeah, UTS#18 actually used to have a level 3 (custom tailoring), but they removed it.
I'm content with level 1 support. The regex crate is just about there and that actually makes it have better Unicode support than the vast majority of regex engines. :-)
Level 2 is indeed hard.