[GHC] #7093: Exception when encountering instance declarations without class name

[GHC]

#7093: Exception when encountering instance declarations without class name
--------------------------------+-------------------------------------------
 Reporter:  guest               |          Owner:                   
     Type:  bug                 |         Status:  new              
 Priority:  normal              |      Component:  Compiler (Parser)
  Version:  7.4.1               |       Keywords:                   
       Os:  Unknown/Multiple    |   Architecture:  Unknown/Multiple 
  Failure:  Compile-time crash  |       Testcase:                   
Blockedby:                      |       Blocking:                   
  Related:                      |  
--------------------------------+-------------------------------------------
 '''Code'''

 {{{
 instance Bounded b => (a -> b) where
  minBound = const minBound
  maxBound = const maxBound
 }}}

 GHC 7.4.1 "crashes" with an exception if the class name
 is missing.


 {{{
 *** Exception: compiler/rename/RnSource.lhs:429:14-81: Irrefutable pattern
 failed for pattern Data.Maybe.Just (inst_tyvars,
                                                         _,
                                                         SrcLoc.L _ cls,
                                                         _)

 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7093>
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