id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
5717,ScopedTypeVariables and PolyKinds,dreixel,,"The following code panics:
{{{
{-# LANGUAGE ScopedTypeVariables        #-}
{-# LANGUAGE PolyKinds                  #-}

module Bug2 where


data TypeRep = TypeRep

data Proxy t = Proxy

typeRep :: Proxy a -> TypeRep
typeRep Proxy = TypeRep

-- This one works fine:
typeOf :: forall a. a -> TypeRep
typeOf _ = typeRep (Proxy :: Proxy a)

-- But this one panics!
typeOf1 :: forall t a. t a -> TypeRep
typeOf1 _ = typeRep (Proxy :: Proxy t)

{-
panic! (the 'impossible' happened)
  (GHC version 7.5.20111216 for x86_64-unknown-linux):
        tyConKind ghc-prim:GHC.Prim.BOX{(w) tc 347}
-}
}}}
I believe the problem is an interaction between !ScopedTypeVariables and !PolyKinds.",bug,closed,normal,7.6.1,Compiler,7.3,fixed,PolyKinds,jpm@…,Unknown/Multiple,Unknown/Multiple,None/Unknown,Unknown,polykinds/T5717,,,"#5768, #5769, #5770"