#15008: Type synonyms with hidden, determined type variables -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Research | needed Component: Compiler | Version: 8.5 Resolution: | Keywords: 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 consider this solved by QuantifiedConstraints {{{#!hs a :: (MonadReader r m, Show r) => m String a = fmap show ask }}} becomes {{{#!hs -- A type synonym works but is less useful class (forall xx. (MonadReader xx m, Show xx)) => MyMonad m instance (forall xx. (monadReader xx m, Show xx)) => MyMonad m b :: MyMonad m => m String b = fmap show ask }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15008#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler