hxt-9.3.1.1: A collection of tools for processing XML with Haskell.

Portabilityportable
Stabilityexperimental
MaintainerUwe Schmidt (uwe\@fh-wedel.de)
Safe HaskellSafe-Inferred

Control.Arrow.ArrowIO

Description

Lifting of IO actions to arrows

Synopsis

Documentation

class Arrow a => ArrowIO a whereSource

the interface for converting an IO action into an arrow

Methods

arrIO :: (b -> IO c) -> a b cSource

construct an arrow from an IO action

arrIO0 :: IO c -> a b cSource

construct an arrow from an IO action without any parameter

arrIO2 :: (b1 -> b2 -> IO c) -> a (b1, b2) cSource

construction of a 2 argument arrow from a binary IO action | | example: a1 &&& a2 >>> arr2 f

arrIO3 :: (b1 -> b2 -> b3 -> IO c) -> a (b1, (b2, b3)) cSource

construction of a 3 argument arrow from a 3-ary IO action | | example: a1 &&& a2 &&& a3 >>> arr3 f

arrIO4 :: (b1 -> b2 -> b3 -> b4 -> IO c) -> a (b1, (b2, (b3, b4))) cSource

construction of a 4 argument arrow from a 4-ary IO action | | example: a1 &&& a2 &&& a3 &&& a4 >>> arr4 f

Instances

class (Arrow a, ArrowIO a) => ArrowIOIf a whereSource

the interface for converting an IO predicate into a list arrow

Methods

isIOA :: (b -> IO Bool) -> a b bSource

builds an arrow from an IO predicate

if the predicate holds, the single list containing the input is returned, else the empty list, similar to isA

Instances