#14968: QuantifiedConstraints: Can't be RHS of type family instances -------------------------------------+------------------------------------- Reporter: josef | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.5 checker) | Keywords: Resolution: | QuantifiedConstraints Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #9269 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): This compiles {{{#!hs type family Functors (fs :: [(Type -> Type) -> Type -> Type]) :: Constraint type instance Functors '[] = (() :: Constraint) type instance Functors (t:ts) = (LvlUp Functor t, Functors ts) class (forall x. cls x => cls (f x)) => LvlUp cls f instance (forall x. cls x => cls (f x)) => LvlUp cls f }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14968#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler