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


-- | Translate pull-based stream folds into push-based iteratees.
--   
--   Translate pull-based folds from the "streaming" package into
--   push-based folds from the "foldl" package.
@package streaming-eversion
@version 0.2.0.0


-- | Most pull-to-push transformations in this module require functions
--   that are polymorphic over a monad transformer.
--   
--   Because of this, some of the type signatures look scary, but actually
--   many (suitably polymorphic) operations on <a>Stream</a>s will unify
--   with them.
--   
--   To get "interruptible" operations that can exit early with an error,
--   put a <a>ExceptT</a> transformer just below the polymorphic monad
--   transformer. In practice, that means lifting functions like
--   <a>throwE</a> and <a>hoistEither</a> a number of times.
--   
--   Inspired by
--   <a>http://pchiusano.blogspot.com.es/2011/12/programmatic-translation-to-iteratees.html</a>
module Streaming.Eversion

-- | A stream-folding function that can be turned into a pure, push-based
--   fold.
data Eversible a x
eversible :: (forall m r. Monad m => Stream (Of a) m r -> m (Of x r)) -> Eversible a x
evert :: Eversible a x -> Fold a x

-- | Like <a>Eversible</a>, but gives the stream-folding function access to
--   a base monad.
--   
--   <pre>
--   &gt;&gt;&gt; :{
--       let consume stream = lift (putStrLn "x") &gt;&gt; S.effects stream
--       in  L.foldM (evertM (eversibleM_ consume)) ["a","b","c"]
--       :}
--   x
--   </pre>
--   
--   Note however that control operations can't be lifted through the
--   transformer.
data EversibleM m a x
eversibleM :: (forall t r. (MonadTrans t, Monad (t m)) => Stream (Of a) (t m) r -> t m (Of x r)) -> EversibleM m a x
eversibleM_ :: (forall t r. (MonadTrans t, Monad (t m)) => Stream (Of a) (t m) r -> t m r) -> EversibleM m a ()
evertM :: Monad m => EversibleM m a x -> FoldM m a x

-- | Like <a>EversibleM</a>, but gives the stream-consuming function the
--   ability to use <a>liftIO</a>.
--   
--   <pre>
--   &gt;&gt;&gt; L.foldM (evertMIO (eversibleMIO_ S.print)) ["a","b","c"]
--   "a"
--   "b"
--   "c"
--   </pre>
data EversibleMIO m a x
eversibleMIO :: (forall t r. (MonadTrans t, MonadIO (t m)) => Stream (Of a) (t m) r -> t m (Of x r)) -> EversibleMIO m a x
eversibleMIO_ :: (forall t r. (MonadTrans t, MonadIO (t m)) => Stream (Of a) (t m) r -> t m r) -> EversibleMIO m a ()
evertMIO :: MonadIO m => EversibleMIO m a x -> FoldM m a x

-- | A stream-transforming function that can be turned into
--   fold-transforming function.
data Transvertible a b
transvertible :: (forall m r. Monad m => Stream (Of a) m r -> Stream (Of b) m r) -> Transvertible a b
transvert :: Transvertible b a -> (forall x. Fold a x -> Fold b x)

-- | Like <a>Transvertible</a>, but gives the stream-transforming function
--   access to a base monad.
--   
--   Note however that control operations can't be lifted through the
--   transformer.
data TransvertibleM m a b
transvertibleM :: (forall t r. (MonadTrans t, Monad (t m)) => Stream (Of a) (t m) r -> Stream (Of b) (t m) r) -> TransvertibleM m a b

-- | Recover the stored function, discarding the transformer.
runTransvertibleM :: TransvertibleM m a b -> (forall r. Monad m => Stream (Of a) m r -> Stream (Of b) m r)
transvertM :: Monad m => TransvertibleM m b a -> (forall x. FoldM m a x -> FoldM m b x)

-- | Like <a>TransvertibleM</a>, but gives the stream-transforming function
--   the ability to use <a>liftIO</a>.
data TransvertibleMIO m a b
transvertibleMIO :: (forall t r. (MonadTrans t, MonadIO (t m)) => Stream (Of a) (t m) r -> Stream (Of b) (t m) r) -> TransvertibleMIO m a b
runTransvertibleMIO :: TransvertibleMIO m a b -> (forall r. MonadIO m => Stream (Of a) m r -> Stream (Of b) m r)
transvertMIO :: (MonadIO m) => TransvertibleMIO m b a -> (forall x. FoldM m a x -> FoldM m b x)
instance GHC.Base.Functor (Streaming.Eversion.Eversible a)
instance Data.Profunctor.Unsafe.Profunctor Streaming.Eversion.Eversible
instance GHC.Base.Functor (Streaming.Eversion.EversibleM m a)
instance Data.Profunctor.Unsafe.Profunctor (Streaming.Eversion.EversibleM m)
instance GHC.Base.Functor (Streaming.Eversion.EversibleMIO m a)
instance Data.Profunctor.Unsafe.Profunctor (Streaming.Eversion.EversibleMIO m)
instance GHC.Base.Functor (Streaming.Eversion.Transvertible a)
instance Data.Profunctor.Unsafe.Profunctor Streaming.Eversion.Transvertible
instance Control.Category.Category Streaming.Eversion.Transvertible
instance Control.Category.Category (Streaming.Eversion.TransvertibleM m)
instance GHC.Base.Functor (Streaming.Eversion.TransvertibleM m a)
instance Data.Profunctor.Unsafe.Profunctor (Streaming.Eversion.TransvertibleM m)
instance Control.Category.Category (Streaming.Eversion.TransvertibleMIO m)
instance GHC.Base.Functor (Streaming.Eversion.TransvertibleMIO m a)
instance Data.Profunctor.Unsafe.Profunctor (Streaming.Eversion.TransvertibleMIO m)


-- | Like <a>Streaming.Eversion</a>, but for Producer folds and
--   transformations.
module Streaming.Eversion.Pipes
pipeEversible :: (forall m r. Monad m => Producer a m r -> m (x, r)) -> Eversible a x
evert :: Eversible a x -> Fold a x
pipeEversibleM :: (forall t r. (MonadTrans t, Monad (t m)) => Producer a (t m) r -> t m (x, r)) -> EversibleM m a x
pipeEversibleM_ :: (forall t r. (MonadTrans t, Monad (t m)) => Producer a (t m) r -> t m r) -> EversibleM m a ()
evertM :: Monad m => EversibleM m a x -> FoldM m a x
pipeEversibleMIO :: (forall t r. (MonadTrans t, MonadIO (t m)) => Producer a (t m) r -> t m (x, r)) -> EversibleMIO m a x
pipeEversibleMIO_ :: (forall t r. (MonadTrans t, MonadIO (t m)) => Producer a (t m) r -> t m r) -> EversibleMIO m a ()
evertMIO :: MonadIO m => EversibleMIO m a x -> FoldM m a x
pipeTransvertible :: (forall m r. Monad m => Producer a m r -> Producer b m r) -> Transvertible a b
transvert :: Transvertible b a -> (forall x. Fold a x -> Fold b x)
pipeTransvertibleM :: (forall t r. (MonadTrans t, Monad (t m)) => Producer a (t m) r -> Producer b (t m) r) -> TransvertibleM m a b
transvertM :: Monad m => TransvertibleM m b a -> (forall x. FoldM m a x -> FoldM m b x)
pipeTransvertibleMIO :: (forall t r. (MonadTrans t, MonadIO (t m)) => Producer a (t m) r -> Producer b (t m) r) -> TransvertibleMIO m a b
transvertMIO :: (MonadIO m) => TransvertibleMIO m b a -> (forall x. FoldM m a x -> FoldM m b x)