Control.Arrow.ArrowIO

Lifting of IO actions to arrows

classclass Arrow a => ArrowIO (a :: Type -> Type -> Type) where

the interface for converting an IO action into an arrow

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

Instances2ArrowIO

classclass (Arrow a, ArrowIO a) => ArrowIOIf (a :: Type -> Type -> Type) where

the interface for converting an IO predicate into a list arrow

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

Instances2ArrowIOIf