type instance doesn't work when the type is (->)
This doesn't work in 7.0.0.20100924. It works fine in 6.12.3.
{-# LANGUAGE TypeFamilies #-}
type family T t :: * -> * -> *
type instance T Bool = (->)
f :: T Bool Bool Bool
f = notThis is the error:
Couldn't match type `T Bool' with `(->)'
Expected type: T Bool Bool Bool
Actual type: Bool -> Bool
In the expression: not
In an equation for `f': f = not