[GHC] #13669: Identifier "Otherwise" in guarded equation can crash a program

[GHC]

#13669: Identifier "Otherwise" in guarded equation can crash a program
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        Reporter:  vanto             |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Other             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 You could replace `otherwise` in the ticket description with any other
 identifier provided by `Prelude` and the same argument will apply.
 However, I really don't think this is an argument for adding complexity to
 the language.

 In the case that `Prelude` is imported unqualified the user will be faced
 with an ambiguity error and there will be no confusion. If they really do
 import `Prelude` qualified and define or otherwise import another
 `otherwise`, then who are we to say they shouldn't? I've never heard of
 anyone complain of being confused by `otherwise`, or any other
 `Prelude`-defined identifier, not behaving as expected for this reason.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13669#comment:2>
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