Regexes are not fundamentally hard. People make regexes hard by trying to parse things by sight rather than finding a spec. If you have a spec, and it can be parsed by a regular expression, they are pretty damn rote to implement.

If you aren’t working from a specified input grammar, the task is going to be borderline impossible no matter the tool and you’re going to have a bad time. If you aren’t working with a regular grammar, this is the wrong tool for the job and again you’re going to have a bad time.

A hint; if you find yourself using `.`, you are probably shooting yourself in the foot.