#11740: RFC kind synonyms -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Resolution: wontfix | 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): {{{#!hs type Monadish = Type -> Type type Transformer = Monadish -> Monadish }}} with many examples from Edward's work on [https://www.reddit.com/r/haskell/comments/50rxci/edward_kmett_monad_homomorp... monad morphisms] {{{#!hs newtype Tensor :: Transformer -> Transformer -> Transformer where Tensor :: s (t m) a -> Tensor s t m a class MonadTrans (t :: Transformer) class Commute (s :: Transformer) (t :: Transformer) where commute :: Monad m => s (t m) a -> t (s m) a newtype StateT s :: Transformer where StateT :: (s -> m (a, s)) -> StateT s m a newtype WriterT w :: Transformer where WriterT :: m (a, w) -> WriterT w m a }}} etc. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11740#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler