[GHC] #8018: GHC hangs with recursive dependency in closed type family

[GHC]

#8018: GHC hangs with recursive dependency in closed type family
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Reporter:  goldfire          |          Owner:  goldfire        
    Type:  bug               |         Status:  new             
Priority:  normal            |      Component:  Compiler        
 Version:  7.7               |       Keywords:                  
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
 Failure:  None/Unknown      |      Blockedby:                  
Blocking:                    |        Related:                  
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 The following code hangs GHC:

 {{{
 {-# LANGUAGE TypeFamilies #-}

 data Foo a = Bar (F a)

 type family F a where
   F (Foo a) = Bool
 }}}

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Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/8018>
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