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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 GHC.TypeLits data Container (xs::[*]) = Container I load it up in ghci, then I type the following command: ghci> :t undefined :: Container '[String,String,String,String,String] Unfortunately, ghci gives me the rather ugly looking: :: Container ((':) * String ((':) * String ((':) * String ((':) * String ((':) * String ('[] *)))))) ghci has removed the sugar for type level strings. Is there any way to prevent ghci from doing this and giving me just the pretty version? On a related note, lets say I create a type level Replicate function data Nat1 = Zero | Succ Nat1 type family Replicate (n::Nat1) x :: [*] type instance Replicate Zero x = '[] type instance Replicate (Succ n) x = x ': (Replicate n x) type LotsOfStrings = Replicate (Succ (Succ (Succ (Succ (Succ Zero))))) String Now, when I ask ghci for a type using LotsOfStrings : ghci> :t undefined :: Container LotsOfStrings ghci is nice and gives me the pretty result: undefined :: Container LotsOfStrings But if I ask for the Replicate d version, ghci> :t undefined :: Container (Replicate (Succ (Succ (Succ (Succ (Succ Zero))))) String) ghci substitutes in for the type family when it didn't do that for the type synonym: :: Container ((':) * [Char] ((':) * [Char] ((':) * [Char] ((':) * [Char] ((':) * [Ch

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