[quotemstr]

It drives me nuts when a developer documents something or other as being a "regex" but doesn't mention which dialect of regulation expression he's talking about. This habit is particularly common in the Rust, JavaScript, and Python communities, which seem to forget that their language's regular expression language isn't universal.

[zahlman]

Why? Of course it means the dialect that is most directly supported by that language (by builtins or the standard library). And why should they have to consider other dialects? They aren't reading regexes from user input (or they'd be a lot more concerned about sanitization, catastrophic backtracking etc.), and their fellow developers all grok the conventions.

[bartread]

I’d imagine precisely because they might be collecting regexes from user input such as parameter values or search terms, and the user may not know or care which technology your tool or service is built with. However, they will need to know which regex dialect(s) you support.

And I’d further bet that people who are casual about specifying that are relatively strongly correlated with people who are casual about santization, catastrophic backtracking, etc. (At least based on code I’ve seen over the decades.)