[steveklabnik]

I recently did something similar, but different: gave Claude some code examples of a Rust-like language, it wrote a recursive descent parser for me. That was a one-shot, though it's a very simple language.

After more features were added, I decided I wanted BNF for it, so it went and wrote it all out correctly, after the fact, from the parser implementation.

[Verdex]

Can you give more info?

How big of a number is "some"?

Also what kind of prompts were you feeding it? Did you describe it as Rust like? Anything else you feel is relevant.

[Is there a GitHub link? I'm more than happy to do the detective work.]

[steveklabnik]

Like three or four. very simple language: main function whos value is the error code, functions of one argument returning one value, only ints, basic control flow and math.

I just opened the repo, here's the commit that did what I'm talking about: https://github.com/steveklabnik/rue/commit/5742e7921f241368e...

Well, the second part anyway, with the grammar. It writing the lexer starts as https://github.com/steveklabnik/rue/commit/a9bce389ea358365f..., it was basically this program.

If I wrote down the prompts, I'd share them, but I didn't.

Please ignore the large amount of llm bullshit in here, since it was private while I did this, I wasn't really worried about how annoying and slightly wrong the README etc was. HEAD is better in that regard.

[Verdex]

Thanks