[GHC] #13929: GHC panic with levity polymorphism

[GHC]

#13929: GHC panic with levity polymorphism
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        Reporter:  vagarenko         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.2
       Component:  Compiler          |              Version:  8.2.1-rc2
      Resolution:                    |             Keywords:  TypeInType,
                                     |  LevityPolymorphism
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 vagarenko):

 Replying to [comment:12 goldfire]:
 > It looks to me that the runtime representation of `x` and `y` can't be
 known at compile time -- these arguments are levity-polymorphic, which is
 problematic. Do you see otherwise?
 `x, y :: f p` where `f :: Type -> Type` and `p :: Type` so they are always
 lifted, right?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13929#comment:13>
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