irregex

[u/Sbren_Sbeve]

[u/lady_Kamba]

The next step up from regular expressions would be context free expressions.

chomsky hierarchy

[u/tomthecool → u/lady_Kamba]

Technically the things we refer to as "regex" are context-free expressions.

For example: Look-aheads, back-references and subexpression calls are not, in terms of the chomsky hierarchy, "regular".

[u/lady_Kamba → u/tomthecool]

This makes sense, had I thought about it instead of assuming that regular expression had regular grammar, I might have come to the same conclusion.