[GHC] #15474: Error message mentions Any

[GHC]

#15474: Error message mentions Any
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        Reporter:  monoidal          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  low               |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Poor/confusing    |  Unknown/Multiple
  error message                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 > So why doesn't something like that happen for Forall?

 Ah, I think it's because

 * The kind of `Forall`'s RHS is just `Type`
 * And we do kind-generalise that kind; it has no free kind variables, so
 no kind-generalisation actually happens.

 And in any case the decl
 {{{
 type Forall k = forall (t :: k). Proxy @k t
 }}}
 gives `Forall` the ambiguous kind `Forall :: forall k. Type`, which will
 do no one any good.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15474#comment:3>
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