Control.Monad.Consumer

A monad transformer for the [partial] consumption of Lists. The interface closely mimics iterators in languages such as Python.

It is often nicer to avoid using Consumer and to use folds and higher-order functions instead.

Documentation

data ConsumerT v m a

A monad tranformer for consuming Lists.

Instances

MonadTrans (ConsumerT v)

Monad m => Monad (ConsumerT v m)

Monad m => Functor (ConsumerT v m)

Monad m => Applicative (ConsumerT v m)

MonadIO m => MonadIO (ConsumerT v m)

evalConsumerT :: List l => ConsumerT v (ItemM l) a -> l v -> ItemM l a

Consume a ListT

next :: Monad m => ConsumerT v m (Maybe v)

Consume/get the next value

consumeRestM :: Monad m => ConsumerT a m b -> ConsumerT a m (m b)

Return an instance of the underlying monad that will use the given ConsumerT to consume the remaining values. After this action there are no more items to consume (they belong to the given ConsumerT now)