FFI binding to Google's RE2. Matching runs in linear time, so no catastrophic backtracking. Here is a validator that ships in a lot of Dart code. It checks that a string is a list of words separated by single spaces: final ok = RegExp ( r'^(\w+\s?)*$' ); It works. Type a name, a tag list, a short label, and it returns true or false quickly. Then someone sends 31 characters of x with no trailing separator and the isolate stops answering. I timed it. On Apple S...