Higher kinded Void

[ajnsit]

I currently have some code for which I require a uninhabitable Functor. I currently just use -

data VoidF a
instance Functor VoidF where
  fmap = undefined

Is it possible to have higher kinded versions of Void to use in this situation with appropriate Functor and other instances? Perhaps even Void1 with kind * -> *, Void2 with kind * -> * -> * etc.

[tomjaguarpaw]

You could use Const Void, Const (Const Void) etc.. (Const is in Control.Applicative)

[ekmett]

I think Const Void is the best "official" answer for this for now. It should have all the right instances.

[ajnsit]

Yes that's perfect! Thanks! It would be nice to have a blurb about using Const for higher kinded Void so it's easier to find.

[ekmett]

Since Void has moved into base, this package here is more or less just in maintenance mode. I'd take a patch that included a documentation blurb, but I wouldn't expect it to get too well seen out here.