[chopin]

I like the article much but I am missing some statements around IDE. What I like about typed languages is the code completion and refactoring it enables when used in a good IDE. Code completion also enables me to "explore" what is possible at the current location. Are there any good IDE's out there for Haskell?

[travv0]

I find VS Code with the Haskell extension to be very good for displaying type signatures, code completion and navigation, etc. Holes (which are covered by the article) are the go-to way to see what's possible at the current location. You type an underscore in your code and the compiler tells you a bunch of information about what goes there including things you could put there that would typecheck.