It depends on the circumstances and requirements but I’d still reply with:
I'd say that regex should be used if they can make a significant difference and you're aware of the scope of the problem being solved by it. That's where Cloudflare went wrong, I'd say. I use it for url formatting so even if it goes wrong, all I get is a 404 hopefully :P
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.