Edward Kmett
On Mon, Jun 11, 2012 at 9:58 PM, AntC
wrote: [snip ...]
Could we have :k (->) :: OpenKind -> * -> * -- why not?
I don't quite understand why you would want arbitrary kinded arguments, but only in negative position.
Thanks Edward, oops I've used the wrong terminology, sorry for the confusion. I didn't mean OpenKind but AnyKind. I put that only in a negative position more to sharpen the question, but also because I assumed the result from (->) would have to be grounded in Kind *; and then at least one of its arguments would also have to be grounded in Kind *. I think perhaps(?) more PolyKindness is on the horizon: http://hackage.haskell.org/trac/ghc/wiki/GhcKinds (section on GADKs, and sub- pages on KindPolymorphism and ExplicitTypeApplication). I guess GHC is getting there by small steps, and doesn't yet have powerful enough Kind refinement nor Kind equality constraints, nor interleaving of Type and Kind inference.