[GHC] #13601: GHC errors but hangs

21 Apr 2017


      #13601: GHC errors but hangs
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           Reporter:  Iceland_jack   |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 {{{#!hs
 {-# LANGUAGE TypeFamilies, DataKinds, TypeInType #-}

 import GHC.Exts
 import Prelude (Bool(True,False),Integer,Ordering,undefined)
 import qualified Prelude
 import Data.Kind

 --------------------
 -- class hierarchy

 type family
   Rep (rep :: RuntimeRep) :: RuntimeRep where
   -- Rep IntRep         = IntRep
   -- Rep DoubleRep      = IntRep
   -- Rep PtrRepUnlifted = IntRep
   -- Rep PtrRepLifted   = PtrRepLifted

 class Boolean (Logic a) => Eq (a :: TYPE rep) where
   type Logic (a :: TYPE rep) :: TYPE (Rep rep)
   (==) :: a -> a -> Logic a

 class Eq a => POrd (a :: TYPE rep) where
   inf :: a -> a -> a

 class POrd a => MinBound (a :: TYPE rep) where
   minBound :: () -> a

 class POrd a => Lattice (a :: TYPE rep) where
   sup :: a -> a -> a

 class (Lattice a, MinBound a) => Bounded (a :: TYPE rep) where
   maxBound :: () -> a

 class Bounded a => Complemented (a :: TYPE rep) where
   not :: a -> a

 class Bounded a => Heyting (a :: TYPE rep) where
   infixr 3 ==>
   (==>) :: a -> a -> a

 class (Complemented a, Heyting a) => Boolean a

 (||) :: Boolean a => a -> a -> a
 (||) = sup

 (&&) :: Boolean a => a -> a -> a
 (&&) = inf
 }}}

 hangs with

 {{{
 $ ghci a.hs
 GHCi, version 8.0.1: http://www.haskell.org/ghc/  :? for help
 [1 of 1] Compiling Main             ( a.hs, interpreted )

 a.hs:18:16: error:  C-c C-cInterrupted.
 }}}

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13601
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