[GHC] #12448: Allow partial application of bidirectional pattern synonyms

30 Jul 2016


      #12448: Allow partial application of bidirectional pattern synonyms
-------------------------------------+-------------------------------------
           Reporter:  Iceland_jack   |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.1
           Keywords:                 |  Operating System:  Unknown/Multiple
  PatternSynonyms                    |
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 {{{#!hs
 type Product3 = (,,)
 }}}

 Allow
 {{{#!hs
 pattern Product3 :: a -> b -> c -> Product3 a b c
 pattern Product3 = (,,)
 }}}

 to mean
 {{{#!hs
 pattern Product3 :: a -> b -> c -> Product3 a b c
 pattern Product3 x y z = (x, y, z)
 }}}

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Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12448
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