27 Jan
2016
27 Jan
'16
5:11 a.m.
`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) in other words, if class expects (a -> b) with any a, instance must not constrain a. as opposed to ... a => a -> b which seems ok