[chrischen]

Actually I found the coding models to work really well with these languages. And the type systems are not actually complex. Ocaml's type system is actually really simple, which is probably why the compiler can be so fast. Even back in the "beta" days of Copilot, despite being marketed as Python only, I found it worked for Ocaml syntax and worked just as well.

The coding models work really well with esoteric syntaxes so if the biggest hurdle to adoption of haskell was syntax, that's definitely less of a hurdle now.

> Instead, you're writing non-trivial proofs about all possible runs of the program.

All possible runs of a program is exactly what HM type systems type check for. This fed into the coding model automatically iterates until it finds a solution that doesn't violate any possible run of the program.

[antonvs]

There's a reason I mentioned Haskell and Rust specifically. You're right, OCaml's type system is simpler in some relevant respects, and may avoid the issues that I was alluding to. I haven't worked with OCaml for a number of years, since before the LLM boom.

The presence of type classes in Haskell and traits in Rust, and of course the memory lifetime types in Rust, are a big part of the complexity I mentioned.

(Edit: I like type classes and traits. They're a big reason I eventually settled on Haskell over OCaml, and one of the reasons I like Rust. I'm also not such a fan of the "O" in OCaml.)

> All possible runs of a program is exactly what HM type systems type check for.

Yes, my point was this can be a more difficult goal to achieve.

> This fed into the coding model automatically iterates until it finds a solution that doesn't violate any possible run of the program.

Only if the model is able to make progress effectively. I have some amusing transcripts of the opposite situation.

[chrischen]

I also try to do verbose type classes using Ocaml's module system and it's been handling these patterns pretty well. My guess is there is probably good documentation / training data in there for these patterns since they are well documented. I haven't actually used coding agents with Haskell yet so it's possible that Ocaml's verbosity helps the agent.