ConstraintKinds and default associated empty constraints
Bas van Dijk
v.dijk.bas at gmail.com
Thu Dec 22 10:37:34 CET 2011
On 22 December 2011 09:31, Simon Peyton-Jones <simonpj at microsoft.com> wrote:
> What about
> class Functor f where
> type C f :: * -> Constraint
> type C f = ()
> After all, just as (Ord a, Show a) is a contraint, so is ().
But there's a kind mis-match there. `C f` should have kind `* ->
Constraint` but () has kind *. Or do I have to enable some language
extension to make this work?
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