[GHC] #11275: :kind! doesn't reduce type families with poly-kinded return kinds

[GHC]

#11275: :kind! doesn't reduce type families with poly-kinded return kinds
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        Reporter:  RyanGlScott       |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  GHCi              |              Version:  7.10.3
      Resolution:  invalid           |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by RyanGlScott):

 * status:  new => closed
 * resolution:   => invalid


Comment:

 Oh, that is a very good point, and GHCi agrees with you:

 {{{
 $ /opt/ghc/head/bin/ghci
 GHCi, version 7.11.20151220: http://www.haskell.org/ghc/  :? for help
 λ> :set -XPolyKinds -XTypeFamilies
 λ> type family Hm :: k where Hm = Int
 λ> :kind! (Hm :: *)
 (Hm :: *) :: *
 = Int
 }}}

 I just didn't realize that `Hm = Int` forced the return kind to be `*`,
 which made `Hm` incomplete, since it doesn't have cases for return kinds
 other than `*`. I'd probably have been less likely to make this mistake if
 #10116 was fixed, but that's a separate issue.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11275#comment:2>
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