Ah yeah that's a good one! It does very likely have enormous implications for performance though. I wonder if I should add it as an opt-in feature to ripgrep. Although its support will be inherently limited in some capacity since character classes will always be limited to matching a single codepoint. (i.e., No UTS#18 Level 2 support.)

Have you found folks using these particular Unicode features in practice? I don't think anyone has request it for ripgrep.