[GHC] #12094: Unlifted types and pattern synonym signatures

[GHC]

#12094: Unlifted types and pattern synonym signatures
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        Reporter:  akio              |                Owner:
            Type:  bug               |               Status:  merge
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |             Keywords:
      Resolution:                    |  PatternSynonyms
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2255
       Wiki Page:                    |
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Comment (by Iceland_jack):

 Bidirectional form also works

 {{{#!hs
 -- ghci> let a@(I# Zero) = I# Zero in a
 -- 0
 pattern Zero = 0#
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12094#comment:5>
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