[GHC] #15558: Locally handling an empty constraint

[GHC]

#15558: Locally handling an empty constraint
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        Reporter:  Ericson2314       |                Owner:  (none)
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:  ⊥
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  error/warning at compile-time      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Ashley Yakeley):

 Hmm, this seemed to work with 8.4.3:

 {{{
 bar :: Bar Int
 bar = Bar 0 undefined

 g' = \case
   X -> bar
   Y -> Bar [] False
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15558#comment:1>
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