Control.Arrow.IOStateListArrow

Description

Implementation of arrows with IO and a state

Synopsis

Documentation

newtype IOSLA s a b Source

list arrow combined with a state and the IO monad

Constructors

IOSLA
Fields runIOSLA :: s -> a -> IO (s, [b])

liftSt :: IOSLA s1 b c -> IOSLA (s1, s2) b cSource

lift the state of an IOSLA arrow to a state with an additional component.

This is uesful, when running predefined IO arrows, e.g. for document input, in a context with a more complex state component.

runSt :: s2 -> IOSLA (s1, s2) b c -> IOSLA s1 b cSource

run an arrow with augmented state in the context of a simple state arrow. An initial value for the new state component is needed.

This is useful, when running an arrow with an extra environment component, e.g. for namespace handling in XML.