[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 goldfire):

 I'm a little uncomfortable that this requires two declarations of the
 name: the `data family Sing :: ...` and the `class Sing ...`.

 More broadly, I think the code might be easier to read using two different
 names, frankly. But maybe others disagree. I don't see any major problems
 with adding it -- it's just a question of programmability (and maintenance
 burden).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14048#comment:3>
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