Emacs used such a thing ~30 years ago. Common wisdom was that it was great when it worked, but a few carelessly written regexes would shoot the performance. If

Emacs used such a thing ~30 years ago. Common wisdom was that it was great when it worked, but a few carelessly written regexes would shoot the performance. If course there'll be some carelessly written ones in any set of >1k regexes.