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


-- | Explicit Sharing of Monadic Effects
--   
--   This package implements a monad transformer for sharing monadic
--   effects.
@package explicit-sharing
@version 0.3.1

module Control.Monad.Sharing

-- | Interface of monads that support explicit sharing.
class Sharing m
share :: (Sharing m, Trans m a a) => m a -> m (m a)

-- | Interface to transform nested monadic data types. The provided |
--   function <tt>trans</tt> is supposed to map the given function on every
--   | monadic argument. The result of <tt>trans</tt> may be of the same
--   type | as the argument but can also be of a different type, e.g. to |
--   convert a value with nested monadic arguments to a corresponding |
--   value without.
class Trans m a b
trans :: (Trans m a b) => (forall c d. (Trans m c d) => m c -> m (m d)) -> a -> m b

-- | Lifts all monadic effects in nested monadic values to the top | level.
--   If <tt>m</tt> is a monad for non-determinism and the argument a | data
--   structure with nested non-determinism then the result | corresponds to
--   the normal form of the argument.
eval :: (Monad m, Trans m a b) => a -> m b

-- | Data type for lists where both the head and tail are monadic.
data List m a
Nil :: List m a
Cons :: (m a) -> (m (List m a)) -> List m a

-- | The empty monadic list.
nil :: (Monad m) => m (List m a)

-- | Constructs a non-empty monadic list.
cons :: (Monad m) => m a -> m (List m a) -> m (List m a)

-- | Checks if monadic list is empty.
isEmpty :: (Monad m) => m (List m a) -> m Bool

-- | Yields the head of a monadic list. Relies on <tt>MonadPlus</tt>
--   instance | to provide a failing implementation of <tt>fail</tt>.
first :: (MonadPlus m) => m (List m a) -> m a

-- | Yields the tail of a monadic list. Relies on <tt>MonadPlus</tt>
--   instance | to provide a failing implementation of <tt>fail</tt>.
rest :: (MonadPlus m) => m (List m a) -> m (List m a)
instance (Monad m, Trans m a a) => Trans m (List m a) [a]
instance (Monad m, Trans m a a) => Trans m (List m a) (List m a)
instance (Monad m, Trans m a a) => Trans m [m a] [a]
instance (Monad m, Trans m a a) => Trans m [m a] [m a]
instance (Monad m) => Trans m Double Double
instance (Monad m) => Trans m Float Float
instance (Monad m) => Trans m Char Char
instance (Monad m) => Trans m Int Int
instance (Monad m) => Trans m Bool Bool

module Control.Monad.Sharing.Lazy

-- | Continuation-based, store-passing implementation of explicit |
--   sharing. It is an inlined version of <tt>ContT (ReaderT Store m)</tt>
--   | where the result type of continuations is polymorphic.
data Lazy m a

-- | Lifts all monadic effects to the top-level and unwraps the monad |
--   transformer for explicit sharing.
evalLazy :: (Monad m, Trans (Lazy m) a b) => Lazy m a -> m b
instance (Monad m) => Sharing (Lazy m)
instance (MonadPlus m) => MonadPlus (Lazy m)
instance (Monad m) => Monad (Lazy m)