Re: [GHC] #15787: GHC panic using kind application

25 Oct 2018

      #15787: GHC panic using kind application
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.6.1
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by goldfire):

 * cc: mnguyen (removed)
 * keywords:  TypeApplications => TypeInType

Comment:

 Also not My's fault. The following code panics similarly in HEAD:

 {{{#!hs
 {-# Language RankNTypes #-}
 {-# Language TypeApplications #-}
 {-# Language DataKinds        #-}
 {-# Language PolyKinds        #-}
 {-# Language GADTs            #-}
 {-# Language TypeFamilies     #-}

 import Data.Kind

 class Ríki (ob :: Type) where
  type Hom :: ob -> ob -> Type

 data
   Kl_kind :: forall ob . (ob -> ob) -> ob -> Type where
   Kl      :: k -> Kl_kind (m :: ob -> ob) k

 type family
   UnKl (kl :: Kl_kind m k) = (res :: k) where
   UnKl (Kl a) = a
 }}}

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15787#comment:2
GHC http://www.haskell.org/ghc/
The Glasgow Haskell Compiler