[GHC] #9632: Promotable type synonyms (or: synonyms to promoted types)

[GHC]

#9632: Promotable type synonyms (or: synonyms to promoted types)
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       Reporter:  jstolarek          |                   Owner:
           Type:  feature request    |                  Status:  new
       Priority:  normal             |               Milestone:
      Component:  Compiler (Type     |                 Version:
  checker)                           |        Operating System:
       Keywords:                     |  Unknown/Multiple
   Architecture:  Unknown/Multiple   |         Type of failure:
     Difficulty:  Unknown            |  None/Unknown
     Blocked By:                     |               Test Case:
Related Tickets:                     |                Blocking:
                                     |  Differential Revisions:
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 I want to use '''synonyms to promoted types''' in the same places where I
 can use the '''promoted types''':

 {{{#!hs
 {-# LANGUAGE DataKinds, KindSignatures #-}
 module PromotableTypeSynonyms where

 data B = T | F
 data P :: B -> *

 type B' = B
 data P' :: B' -> * -- using B' synonym here is currently not allowed
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9632>
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