> My thought is that if FP languages like OCaml / Haskell / etc. let us compress a lot of information into a small amount of text, then that's better for the context window.

Claude Code’s Haskell style is very verbose; if-then-elsey, lots of nested case-ofs, do-blocks at multiple levels of intension, very little naming things at top-level.

Given a sample of a simple API client, and a request to do the same but for another API, it did very well.

I concluded that I just have more opinions about Haskell than Java or Rust. If it doesn’t look nice, why even bother with Haskell.

I reckon that you could seed it with style examples that take up very little context space. Also, remind it to not enable language pragmas per file when they’re already in .cabal, and similar.