Streaming.Producer

Documentation

newtype Producer m a

A Producer generates values of type a with effects of type m

Constructors

Producer

Fields

• runStream :: m (Stream m a)

Instances

Monad m => Monad (Producer m)

Methods

(>>=) :: Producer m a -> (a -> Producer m b) -> Producer m b

(>>) :: Producer m a -> Producer m b -> Producer m b

return :: a -> Producer m a

fail :: String -> Producer m a

Functor m => Functor (Producer m)

Methods

fmap :: (a -> b) -> Producer m a -> Producer m b

(<$) :: a -> Producer m b -> Producer m a

Monad m => Applicative (Producer m)

Methods

pure :: a -> Producer m a

(<*>) :: Producer m (a -> b) -> Producer m a -> Producer m b

(*>) :: Producer m a -> Producer m b -> Producer m b

(<*) :: Producer m a -> Producer m b -> Producer m a

Show a => Show (Producer Identity a)

Methods

showsPrec :: Int -> Producer Identity a -> ShowS

show :: Producer Identity a -> String

showList :: [Producer Identity a] -> ShowS

data Stream m a

ADT for the produced elements. There are either:

• no element
• one element
• several elements (a "chunk") followed by the next producer

Constructors

Done

One a

More [a] (Producer m a)

Instances

Functor m => Functor (Stream m)

Methods

fmap :: (a -> b) -> Stream m a -> Stream m b

(<$) :: a -> Stream m b -> Stream m a

done :: Applicative m => Producer m a

Constructors

A Producer with no elements

one :: Applicative m => a -> Producer m a

A Producer with one element

more :: Applicative m => [a] -> Producer m a -> Producer m a

A Producer with n elements and another Producer

emit :: Applicative m => [a] -> Producer m a

A Producer with n elements

append :: Applicative m => Producer m a -> Producer m a -> Producer m a

Combinators

Append 2 Producers together

filter :: Monad m => (a -> Bool) -> Producer m a -> Producer m a

Filter the values of a Producer

take :: Monad m => Int -> Producer m a -> Producer m a

Take the first n elements If n <= 0 an empty Producer is returned

drop :: Monad m => Int -> Producer m a -> Producer m a

Drop the first n elements If n <= 0 nothing is dropped

chunk :: Monad m => Int -> Producer m a -> Producer m a

Make sure that the underlying chunks have a size n as much as possible

runList :: Monad m => Producer m a -> m [a]

Observations

The following functions can "run" a Producer to get values back

return a list of values

runChunks :: Monad m => Producer m a -> m [[a]]

return a list of chunks