#14840: QuantifiedConstraints: Can't define class alias -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.5 Resolution: | Keywords: | QuantifiedConstraints wipT2893 Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): I have a hunch this will not be allow, but encoding sums and existentials doesn't work {{{#!hs class (forall sum. (a => sum) => (b => sum) => sum) => Sum a b instance (forall sum. (a => sum) => (b => sum) => sum) => Sum a b class (forall exists. (forall xx. f xx => exists) -> exists) => Exists f instance (forall exists. (forall xx. f xx => exists) -> exists) => Exists f }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14840#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler