Check out Kleenex which also allows you to inline actions in the (regular) grammar, but which promises to only execute them when it has resolved all non-determi

Check out Kleenex which also allows you to inline actions in the (regular) grammar, but which promises to only execute them when it has resolved all non-determinism for the input seen so far: https://kleenexlang.org/ https://kleenexlang.org/ The compiler translates regular grammars with embedded semantic actions to fast C code. Full disclosure: I am one of the authors.