[GHC] #4222: Template Haskell lets you reify supposedly-abstract data types

[GHC]

#4222: Template Haskell lets you reify supposedly-abstract data types
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        Reporter:  simonpj           |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  low               |            Milestone:
       Component:  Template Haskell  |              Version:  6.12.3
      Resolution:                    |             Keywords:
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 mgsloan):

 IMHO being able to reify stuff like this is a feature not a bug.  See, for
 example, the http://hackage.haskell.org/package/true-name package.

 One thing that comes to mind here is just making it a special variety of
 warning when TH references things that are not imported.  This way things
 like the "true-name" package will still be possible, but will cause
 warnings that can be ignored if the user chooses to.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4222#comment:9>
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