21 Dec
2015
21 Dec
'15
9:15 p.m.
...actually, nevermind, it's not a bug after all. It was just me being boneheaded. Since Extract has a polymorphic return kind, there's no way for GHCi to know what the kind of Extract 0 '(Int, Char) will be unless there's a kind ascription. If you be more explicit, then GHCi knows what to do: > :kind! (Extract 0 '(Int, Char) :: *) (Extract 0 '(Int, Char) :: *) :: * = Int > :kind! (Extract 0 '(Int, Char) :: * -> *) (Extract 0 '(Int, Char) :: * -> *) :: * -> * = (TypeError ...) Thanks to Reid Barton for pointing this out to me. Ryan S. ----- [1] https://ghc.haskell.org/trac/ghc/ticket/10116