On Thu, Nov 23, 2017 at 06:19:51PM +0100, Marcus Manning wrote:
> Original I thought a Signature like:
> f :: h a -> h a
> means that h is a higher kinded type just like in Type Classes ( for
> instance f in Functor f).
> But I heard such a meaning is not allowed in normal Haskell functions. What
> instead is the meaning of h a?
you can write that but, since we know nothing about `h` and `a`,
the only possible (non-undefined) function to implement that