Windsurf + Haskell w/ CLI tools has been pretty amazing. Windsurf's agent will loop for minutes on its own to figure out the right structure of a program. You just need to tell it to:
- use the hoogle cli to search for the right types and functions
- include a comprehensive test suite
- run a build after every code change
- run tests after every successful build
GHC + a Claude-based agent is a thing to behold.