[GHC] #14042: Datatypes cannot use a type family in their return kind

[GHC]

#14042: Datatypes cannot use a type family in their return kind
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |             Keywords:  TypeInType,
      Resolution:                    |  TypeFamilies
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 > one would intuitively expect the language to recognize the fact that
 MkFun args Type does in fact expand to something which ends in Type

 Would one?  That requires somewhat sophisticated reasoning about `MkFun`
 doesn't it?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14042#comment:10>
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