Arrow - BHC Documentation

newtype ArrowMonad a b { } #

ArrowMonad (a () b)

The monad induced by ArrowApply.

newtype Kleisli m a b { } #

Kleisli { runKleisli :: a -> m b }

Kleisli arrows of a monad.

class Category a => Arrow a { } #

Methods

arr :: (b -> c) -> a b c

first :: (a b c) -> a (b, d) (c, d)

second :: (a b c) -> a (d, b) (d, c)

*** :: (a b c) -> (a b' c') -> a (b, b') (c, c')

&&& :: (a b c) -> (a b c') -> a b (c, c')

class Arrow a => ArrowZero a { } #

Methods

zeroArrow :: a b c

Arrows with a zero (identity for '<+>').

class Arrow a => ArrowPlus a { } #

Methods

<+> :: (a b c) -> (a b c) -> a b c

Arrows with a plus operation (choice between arrows).

class Arrow a => ArrowChoice a { } #

Methods

left :: (a b c) -> a (Either b d) (Either c d)

right :: (a b c) -> a (Either d b) (Either d c)

+++ :: (a b c) -> (a b' c') -> a (Either b b') (Either c c')

||| :: (a b d) -> (a c d) -> a (Either b c) d

Arrows that support choice (branching on Either).

class Arrow a => ArrowApply a { } #

Methods

app :: a (a b c, b) c

class Arrow a => ArrowLoop a { } #

Methods

loop :: (a (b, d) (c, d)) -> a b c

Arrows with a feedback loop (fixed-point combinator).

x :: { } #

returnA :: (Arrow a) => a b b { } #

O(1). The identity arrow. Equivalent to @arr id@.

^>> :: (Arrow a) => (b -> c) -> (a c d) -> a b d { } #

O(1). Precomposition with a pure function (left to right).

>>^ :: (Arrow a) => (a b c) -> (c -> d) -> a b d { } #

O(1). Postcomposition with a pure function (left to right).

<<^ :: (Arrow a) => (a c d) -> (b -> c) -> a b d { } #

O(1). Precomposition with a pure function (right to left).

^<< :: (Arrow a) => (c -> d) -> (a b c) -> a b d { } #

O(1). Postcomposition with a pure function (right to left).

<*> :: { } #

h :: { } #

leftApp :: (ArrowApply a) => (a b c) -> a (Either b d) (Either c d) { } #

g :: { } #

<+> :: { } #

instance ArrowApply -> { }

instance Arrow a => Functor (ArrowMonad a) { }

instance ArrowLoop -> { }

instance Monad m => Arrow (Kleisli m) { }

instance Monad m => ArrowChoice (Kleisli m) { }

instance Monad m => ArrowApply (Kleisli m) { }

instance MonadPlus m => ArrowZero (Kleisli m) { }