Type family bug?
Simon Peyton Jones
simonpj at microsoft.com
Thu Jan 19 10:02:21 UTC 2017
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
* 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.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the ghc-devs