#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): Did you have something like that in mind? {{{#!hs -- user writes type MyMonad m = (MonadReader r m, Show r) }}} but GHC knows that `r` is determined by `m` so silently {{{#!hs -- GHC transforms it into type MyMonad m = (forall xx. (MonadReader xx m, Show xx)) }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15008#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler