[GHC] #12228: Make newtype polykinded

[GHC]

#12228: Make newtype polykinded
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           Reporter:  dfeuer         |             Owner:
               Type:  feature        |            Status:  new
  request                            |
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.1
  (Type checker)                     |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 I hate having to give up so much top type safety when I use unlifted
 types. It seems to me that I should be able to use `newtype` to create new
 types of kind `#` as well as `*`:

 {{{#!hs
 newtype MyWord# = MyWord# Word#
 newtype GoodStuff# a = GoodStuff (# Int#, a #)
 }}}

 In an ideal world, such types would be in Core (so RULES could see them),
 but I'd be very happy even to just have them in Haskell.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12228>
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