[ ghc-Bugs-992199 ] Template crash on existential types

Bugs item #992199, was opened at 2004-07-16 09:08
Message generated for change (Settings changed) made by simonmar
You can respond by visiting: 
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Category: Template Haskell
Group: 6.2.1
Status: Open
Resolution: None
>Priority: 7
Submitted By: Mike Aizatsky (mm_aa)
Assigned to: Simon Peyton Jones (simonpj)
Summary: Template crash on existential types

Initial Comment:
Windows XP

D:\Tools\ghc>ghc-6.2.1\bin\ghc.exe -fglasgow-exts foo.hs
ghc.exe: panic! (the `impossible' happened, GHC version 6.2.1):
        deSugar/DsMeta.hs:286: Non-exhaustive patterns in function 
repC



module Foo where

import Language.Haskell.THSyntax

class MyInterface a where
        foo :: a -> Int

data AnyMyInterface = forall a. (MyInterface a) => 
AnyMyInterface a

test =
    do{
        d <- unQ(reifyDecl AnyMyInterface)
      ; print d
      }


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