Use `Natural` rather than `Integer` in `GHC.TypeLits`
When the numeric type-literals were implement via GHC.TypeLits there was no Natural type in base yet. But since GHC 7.10 we finally have Natural available in base!
Specifically, the following 3 type-signatures in GHC.TypeLits contain Integers that ought rather be Naturals:
someNatVal :: Integer -> Maybe SomeNat
natVal :: forall n proxy. KnownNat n => proxy n -> Integer
natVal' :: forall n. KnownNat n => Proxy# n -> Integer
Edited by Herbert Valerio Riedel