[supriyo-biswas]

I’m not sure if this response was simply for the sake of replying, with the claims of writing perfect code all the time or how backtracking implementation is uncommon or insane (most languages use backtracking implementations of regexes).

[eru]

Huh? I'm not making any claims of writing perfect code. If you have a sane regular expression matcher, there are no catastrophic cases to avoid.

Regular expression libraries that don't use backtracking are available for many languages. Yes, some languages have bad libraries that use backtracking, too. But bad libraries will always exist, they aren't an excuse when there are more good libraries around then ever before.