#14450: GHCi spins forever -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: closed Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 Resolution: fixed | Keywords: TypeInType, | PolyKinds Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: performance bug | polykinds/T14450 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): Is this an instance of the same bug? Loops on 8.3.20170920 and 8.2 {{{#!hs {-# Language KindSignatures, TypeOperators, PolyKinds, DataKinds, TypeInType, TypeFamilies, AllowAmbiguousTypes #-} import Data.Kind type a-->b = (a, b) -> Type type Cat k = k -> k -> Type class F (f::k-->k') where type D f :: Cat k type C f :: Cat k' f :: D f a a' -> C d (App f a) (App f a') data DupSym0 :: a --> (a, a) type family App (f::a-->b) (x::a) :: b where App DupSym0 a = '(a, a) instance F DupSym0 where type D DupSym0 = (->) }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14450#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler