27 Jan
2016
27 Jan
'16
8:28 a.m.
On Wed, Jan 27, 2016 at 11:11 AM, Imants Cekusins
`fmap` types mean that `a` should be anything, and not something constrained.
just wondering: is it something specific to Functor class or does this hold for any class declaration:
(a -> b) is not the same as ... a => (a -> b)
a => (a -> b) does not really mean anything as far as I know because a is not a constraint (i.e: a typeclass). Perhaps you mean something such as Constraint a => (a -> b)
in other words, if class expects (a -> b) with any a, instance must not constrain a.
However I discovered the `ConstraintKinds` extension which may improve the situation. -- G.