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

[GHC]

#9858: Typeable instances should be kind-aware
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        Reporter:  dreixel           |                   Owner:
            Type:  bug               |                  Status:  merge
        Priority:  highest           |               Milestone:  7.10.2
       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:                    |  typecheck/should_fail/T9858a,
                                     |  should_run/T9858b
                                     |                Blocking:
                                     |  Differential Revisions:  Phab:D652
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Comment (by diatchki):

 This should be fixed in HEAD now.  Please give it a whirl, and let me know
 if you run into any more problems.  The implementation should be what
 Richard discribed:

   * Constraints are OK
   * Impredicative types are not OK (not even things like `Eq Int => Int`)
   * Constraint and normal tuples should have different representations at
 all arities.

 A side-note:  I couldn't figure out how to write the type constructor `(,)
 :: Constraint -> Constraint -> Constraint`, so I had to get creative with
 the testing.  Is that intentional?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9858#comment:94>
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