[GHC] #12429: Pattern synonym parse error should recommend enabling extension

[GHC]

#12429: Pattern synonym parse error should recommend enabling extension
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        Reporter:  agibiansky        |                Owner:
            Type:  bug               |               Status:  new
        Priority:  low               |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
                                     |  PatternSynonyms
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 That sounds very sensible and do-able.  Would anyone like to offer a
 patch?  We have precedents; e.g. a sensible error when people use `forall`
 without `RankNTypes`.

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12429#comment:2>
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