Control.Monad.Consumer

A monad for consuming streams - I believe this is basically just a specialized version of the State monad.

Consumer Monad

newtype Consumer c a

Constructors

Consumer ([c] -> (a, [c]))

Instances

Monad (Consumer c)

Functor (Consumer c)

MonadFix (Consumer c)

Applicative (Consumer a)

MonadConsumer (Consumer c) c

runConsumer :: [c] -> Consumer c a -> (a, [c])

Execute a stateful computation, as a result we get the result of the computation, and the final state.

evalConsumer :: [c] -> Consumer c a -> a

Execute a stateful computation, ignoring the final state.

execConsumer :: [c] -> Consumer c a -> [c]

Execute a stateful computation, just for the side effect.

class Monad m => MonadConsumer m c | m -> c where

Methods

next

Arguments

:: Monad m'

=> m (m' c)

return next element from stream

peek

Arguments

:: Monad m'

=> m (m' c)

peek at next element, but leave it in the stream

poke

Arguments

:: c

-> m c

push and element onto the beginning on the stream

Instances

MonadConsumer (Consumer c) c

Monad m => MonadConsumer (ConsumerT c m) c

Consumer Monad Transformer

newtype ConsumerT c m a

Constructors

ConsumerT

Fields

runConsumerT :: [c] -> m (a, [c])

Instances

MonadTrans (ConsumerT c)

Monad m => Monad (ConsumerT c m)

Monad m => Functor (ConsumerT c m)

MonadPlus m => MonadPlus (ConsumerT c m)

Monad m => Applicative (ConsumerT c m)

MonadIO m => MonadIO (ConsumerT c m)

Monad m => MonadConsumer (ConsumerT c m) c