[GHC] #9093: Type synonym accepted with out-of-scope kind variable

9 May 2014

      #9093: Type synonym accepted with out-of-scope kind variable
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       Reporter:          |             Owner:
  goldfire                |            Status:  new
           Type:  bug     |         Milestone:
       Priority:  normal  |           Version:  7.8.2
      Component:          |  Operating System:  Unknown/Multiple
  Compiler                |   Type of failure:  GHC accepts invalid program
       Keywords:          |         Test Case:
   Architecture:          |          Blocking:
  Unknown/Multiple        |
     Difficulty:          |
  Unknown                 |
     Blocked By:          |
Related Tickets:          |
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 When I say

 {{{
 {-# LANGUAGE PolyKinds #-}

 import Data.Proxy
 import GHC.Exts

 type X = Proxy (Any :: k)
 }}}

 I get no error. If I then ask GHCi about `X` (with `-fprint-explicit-
 kinds`), I see this:

 {{{
 *Main> :i X
 type X = Proxy AnyK (Any AnyK)
 }}}

 I think my original code should be rejected.

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Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9093
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