Control.Arrow.ArrowIO

Lifting of IO actions to arrows

Documentation

class Arrow a => ArrowIO a where

the interface for converting an IO action into an arrow

Methods

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

construct an arrow from an IO action

arrIO0 :: IO c -> a b c

construct an arrow from an IO action without any parameter

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

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)) c

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))) c

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

Instances

ArrowIO IOLA

Arrow (IOSLA s) => ArrowIO (IOSLA s)

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

the interface for converting an IO predicate into a list arrow

Methods

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

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

ArrowIOIf IOLA

(Arrow (IOSLA s), ArrowIO (IOSLA s)) => ArrowIOIf (IOSLA s)