[GHC] #5777: core lint error with arrow notation and GADTs (was: Panic with Arrow Notation and GADTs)

[GHC]

#5777: core lint error with arrow notation and GADTs
--------------------------------+-------------------------------------------
 Reporter:  benmos              |          Owner:               
     Type:  bug                 |         Status:  new          
 Priority:  normal              |      Component:  Compiler     
  Version:  7.4.1-rc1           |       Keywords:  arrows, GADTs
       Os:  MacOS X             |   Architecture:  x86          
  Failure:  Compile-time crash  |       Testcase:               
Blockedby:                      |       Blocking:               
  Related:                      |  
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Comment(by ross):

 Simplified version, avoiding classes:
 {{{
 {-# LANGUAGE Arrows, GADTs #-}
 module ArrowBug5777 where

 import Control.Arrow

 data Value a where BoolVal :: Value Bool

 arrif :: Value Bool -> ()
 arrif = proc BoolVal -> returnA -< ()
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5777#comment:1>
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