[GHC] #14580: GHC panic (TypeInType) (the 'impossible' happened)

[GHC]

#14580: GHC panic (TypeInType) (the 'impossible' happened)
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.3
      Resolution:  fixed             |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  polykinds/T14580
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by simonpj):

 * status:  new => closed
 * testcase:   => polykinds/T14580
 * resolution:   => fixed


Comment:

 HEAD gives
 {{{
 Prelude Data.Kind> type (a <--> b) iso cat = ISO (iso :: cat a b)

 <interactive>:7:31: error:
     • Expected kind ‘Cat a’, but ‘(iso :: cat a b)’ has kind ‘cat a b’
     • In the first argument of ‘ISO’, namely ‘(iso :: cat a b)’
       In the type ‘ISO (iso :: cat a b)’
       In the type declaration for ‘<-->’
 }}}
 probably as a result of the patches I pushed yesterday.   Hurrah.

 I've added a regression test, to be on the safe side.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14580#comment:2>
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