#ghci

Have a module and want to know what functions it exposes without opening up the source? Or what if you don't have the source but want to know what you can do with it?

Simple:

ghci> :load AModule.hs [1 of 1] Compiling Just.AModule ( AModule.hs, interpreted ) Ok, modules loaded: Just.AModule. ghci> -- notice the name of the module loaded ghci> :browse Just.AModule data Cat a = Cat a getName :: Cat a -> a newName :: a -> Cat a

How to: Why does ghci desugar type lists and type families? Can this be selectively disabled?

Why does ghci desugar type lists and type families? Can this be selectively disabled?

I’m trying to make the types ghci displays for my libraries as intuitive as possible, but I’m running into a lot of difficulties when using more advanced type features.

Let’s say I have this code in a file:

{-# LANGUAGE TypeFamilies #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeOperators #-} import…