[GHC] #9858: Typeable instances should be kind-aware

[GHC]

#9858: Typeable instances should be kind-aware
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        Reporter:  dreixel           |                   Owner:  dreixel
            Type:  bug               |                  Status:  new
        Priority:  highest           |               Milestone:  7.10.1
       Component:  Compiler          |                 Version:  7.9
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
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Comment (by int-e):

 Replying to [comment:49 int-e]:
 > {{{
 > f = \(p :: Proxy Proxy) -> typeRep p
 > }}}

 Note that currently, the function has type `Proxy Proxy -> Typeable`. What
 will the type be under the proposed medium term solution?
 If we want full backward compatibility (and I personally don't think we
 should strive for that for examples like this one) then passing hidden
 extra evidence is the only way to go.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9858#comment:50>
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