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  • #5938

Closed
Open
Opened Mar 13, 2012 by Richard Eisenberg@raeDeveloper

Kind variables not allowed in type family instance declarations

I am trying to create a kind-indexed type family, but I cannot use kind variables in my kind annotations:

{-# LANGUAGE PolyKinds, TypeFamilies, DataKinds #-}

type family KindFam a
type instance KindFam (a :: *) = Int
type instance KindFam (a :: Bool) = Bool
type instance KindFam (a :: Maybe k) = Char -- doesn't work
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Version 7.5
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component Compiler (Type checker)
Test case
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Reference: ghc/ghc#5938