[skydhash]

Isn't that what tools like antlr [0], bison[1] do?

[0]: https://www.antlr.org/

[1]: https://www.gnu.org/software/bison/

[jdlshore]

They typically generate generic LALR parsers, not custom recursive descent parsers. I'm no expert, but my understanding is that custom recursive descent parsers have advantages in terms of readability and error message generation.