Evaluated OpenAI Codex for weeks now. It cuts 1/2 the time off my current coding time, largely by producing syntax correct code & reducing lookups to docs/stack/etc.

At the same time, it's hopelessly wrong or broken about 1/3 of the time.

On balance - it is revolutionary. For real world use - it is still very experimental.

Can we ask Codex to write in languages like Haskell where it's hard to make "small" mistakes, because types are catching you? Or does it circumvent that?

If you want to auto-write Haskell, use MagicHaskeller:

http://nautilus.cs.miyazaki-u.ac.jp/~skata/MagicHaskeller.ht...

And whle we're at it, if you want to auto-write Prolog, use my own Louise:

https://github.com/stassa/louise