Kind error when using partial type signatures
Summary
When using a partial type signature I get a kind error, which is surprising.
Steps to reproduce
Compile the following module. The function bar type checks, whereas baz gets a kind error
{-# LANGUAGE RankNTypes #-}
module Bug where
foo :: (Functor g) =>
(forall aa . Num aa => f aa -> g aa) ->
f a -> g (f a)
foo f x = undefined
bar :: (forall aa . Num aa => f aa -> Int -> aa) ->
f a -> Int -> f a
bar f = foo f
baz :: (forall aa . Num aa => f aa -> Int -> aa) ->
f a -> _ -> f a
baz f = foo fEnvironment
- GHC version used:
The Glorious Glasgow Haskell Compilation System, version 8.10.1