Richard

This works

type family F (a :: k)

type instance F Maybe = Char

But this does not.  Surely it should?

type family F (a :: k) where -- = r  | r -> a where

  F Maybe = Char

The latter is rejected with

Foo.hs:6:5: error:

    * Expecting one more argument to `Maybe'

      Expected kind `k', but `Maybe' has kind `* -> *'

    * In the first argument of `F', namely `Maybe'

      In the type family declaration for `F'

If you agree I’ll open a ticket.

Simon