#8565: New GeneralisedNewtypeDeriving needs help with higher rank types -------------------------------------------------+------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Test Case: | Difficulty: typecheck/should_compile/T8565 | Unknown Blocking: | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Comment (by nomeata): I’m working on {{{ instance (forall a. (Coercible t1 t2)) => Coercible (forall a. t1) (forall a. t2) }}} and am almost done, just trying to get the desugarer cope with new type variables in derived constraints. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8565#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler