[GHC] #14048: Data instances of kind Constraint

[GHC]

#14048: Data instances of kind Constraint
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        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #12369            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Iceland_jack):

 Is [https://github.com/ghc-proposals/ghc-
 proposals/pull/32#issuecomment-319175473 Type v Constraint] not a use
 case,

 {{{#!hs
 data family   (=>)
 data instance (=>) :: forall (r :: RuntimeRep). Constraint -> TYPE r ->
 Type
 data instance (=>) :: Constraint -> Constraint -> Constraint
 data instance (=>) :: forall (r :: RuntimeRep). TYPE r -> Constraint ->
 Constraint
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14048#comment:4>
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