[GHC] #11027: GHC API panic (evaluated the place holder for a PostTcType)

[GHC]

#11027: GHC API panic (evaluated the place holder for a PostTcType)
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        Reporter:  rubik             |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  GHC API           |              Version:  7.8.4
      Resolution:                    |             Keywords:  undefined,
                                     |  place holder, posttctype
Operating System:  Linux             |         Architecture:  x86_64
                                     |  (amd64)
 Type of failure:  Runtime crash     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 I'd ask Alan Zimmerman.

 Certainly if you write a wildcard in a pattern match GHC won't evaluate
 that field in a pattern match:
 {{{
 f (C _ x) = ...
 }}}
 the `_` argument of `C` will not be evaluated by `f`.  (It might be
 evaluated for some other reason.)

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11027#comment:2>
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