-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Methods for composing monads.
--   
--   Methods for composing monads.
--   
--   The I/O monad transformer, PlusMonad, and Linear modules are
--   deprecated. Their use is discouraged. This package is now about
--   automatic monad lifting; and includes a rigorous implementation of
--   Luth and Ghani coproducts structured around the Free monad.
@package MonadCompose
@version 0.9.0.0


-- | Eta inverses for some vernacular monads.
module Control.Monad.EtaInverse
class (Monad f) => EtaInverse f
etaInv :: EtaInverse f => f t -> Maybe t
instance Control.Monad.EtaInverse.EtaInverse Data.Functor.Identity.Identity
instance (GHC.Base.Monoid s, GHC.Classes.Eq s) => Control.Monad.EtaInverse.EtaInverse ((,) s)
instance (GHC.Base.Monoid s, GHC.Classes.Eq s, Control.Monad.EtaInverse.EtaInverse f) => Control.Monad.EtaInverse.EtaInverse (Control.Monad.Trans.Writer.Lazy.WriterT s f)
instance Control.Monad.EtaInverse.EtaInverse GHC.Maybe.Maybe
instance Control.Monad.EtaInverse.EtaInverse []
instance Control.Monad.EtaInverse.EtaInverse f => Control.Monad.EtaInverse.EtaInverse (Control.Monad.Trans.Maybe.MaybeT f)
instance GHC.Base.Functor f => Control.Monad.EtaInverse.EtaInverse (Control.Monad.Free.Free f)
instance (GHC.Base.Functor f, Control.Monad.EtaInverse.EtaInverse f2) => Control.Monad.EtaInverse.EtaInverse (Control.Monad.Trans.Free.FreeT f f2)


-- | This *is* monad coproducts (due to Luth and Ghani) unlike the other
--   thing.
module Control.Monad.Coproducts3

-- | A modified free monad giving efficient access to the topmost layer;
--   but otherwise using the machinery of the free monad <tt>f2</tt>.
data Free' f f2 t
Free' :: f (f2 t) -> Free' f f2 t
[unFree'] :: Free' f f2 t -> f (f2 t)
Pure' :: t -> Free' f f2 t

-- | A projection into the underlying free monad construction.
toF2 :: MonadFree f m => Free' f m a -> m a

-- | Given a free construction construct a representation of the monad
--   coproduct in a free mona; it picks out one representative element of
--   each equivalence class in the defining quotient of the monad
--   coproduct.
execCoproduct :: (EtaInverse f, EtaInverse f2, MonadFree (Sum f f2) f3) => Free (Sum f f2) t -> Free' (Sum f f2) f3 t
instance (GHC.Base.Functor f, GHC.Base.Functor f2) => GHC.Base.Functor (Control.Monad.Coproducts3.Free' f f2)
instance (Data.Functor.Classes.Show1 f, Data.Functor.Classes.Show1 f2) => Data.Functor.Classes.Show1 (Control.Monad.Coproducts3.Free' f f2)
instance (GHC.Show.Show (f (f2 t)), GHC.Show.Show (f2 t), GHC.Show.Show t) => GHC.Show.Show (Control.Monad.Coproducts3.Free' f f2 t)
instance (GHC.Base.Functor f, Control.Monad.Free.Class.MonadFree f f2) => GHC.Base.Monad (Control.Monad.Coproducts3.Free' f f2)
instance (GHC.Base.Functor f, Control.Monad.Free.Class.MonadFree f f2) => GHC.Base.Applicative (Control.Monad.Coproducts3.Free' f f2)
instance (GHC.Base.Functor f, Control.Monad.Free.Class.MonadFree f f2) => Control.Monad.Free.Class.MonadFree f (Control.Monad.Coproducts3.Free' f f2)

module Control.Monad.Lifter

-- | An automatic lifter. The idea of automatic lifting is due to Dan
--   Piponi.
class Lifter m n
lf :: Lifter m n => m t -> n t
instance Control.Monad.Lifter.Lifter (GHC.ST.ST GHC.Prim.RealWorld) GHC.Types.IO
instance Control.Monad.Lifter.Lifter GHC.Types.IO GHC.Types.IO
instance Control.Monad.Lifter.Lifter (GHC.ST.ST s) (GHC.ST.ST s)
instance Control.Monad.Lifter.Lifter Data.Functor.Identity.Identity Data.Functor.Identity.Identity
instance (Control.Monad.Trans.Class.MonadTrans n, GHC.Base.Monad x, Control.Monad.Lifter.Lifter m x) => Control.Monad.Lifter.Lifter m (n x)
instance (GHC.Base.Monad x, Control.Monad.Morph.MFunctor m) => Control.Monad.Lifter.Lifter (m Data.Functor.Identity.Identity) (m x)