[GHC] #8968: Pattern synonyms and GADTs

[GHC]

#8968: Pattern synonyms and GADTs
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        Reporter:  kosmikus                   |            Owner:
            Type:  bug                        |           Status:  new
        Priority:  normal                     |        Milestone:
       Component:  Compiler (Type checker)    |          Version:
      Resolution:                             |  7.8.1-rc2
Operating System:  Unknown/Multiple           |         Keywords:
 Type of failure:  GHC rejects valid program  |     Architecture:
       Test Case:                             |  Unknown/Multiple
        Blocking:                             |       Difficulty:  Unknown
                                              |       Blocked By:
                                              |  Related Tickets:
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Comment (by kosmikus):

 FWIW, I was assuming the problem that SPJ describes is the underlying
 problem here. I don't know the implementation, but I find it entirely
 reasonable that pattern synonyms for GADTs will in general require type
 signatures in order to disambiguate between incomparable types. That's why
 I started talking about type signatures for pattern synonyms in the first
 place.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8968#comment:2>
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