[natrys]

Yep peg.el[1] is now built-into Emacs since 30.1 (which is how I came to know of it, but actually the library seems much older) and it makes certain things much simpler and faster to do than before (once you figure out its quirks).

[1] https://github.com/emacs-mirror/emacs/blob/master/lisp/progm...