Safe Haskell	Safe
Language	Haskell2010

Control.Functor.Covariant.Composition.Traversable

Synopsis

class Covariant t => Traversable t where

Documentation

class Covariant t => Traversable t where Source #

Let f :: (Applicative t, Applicative g) => t a -> u a
Let p :: (Pointable t, Pointable g) => t a -> u a

When providing a new instance, you should ensure it satisfies the four laws:
* Naturality of traversing: g . traverse f ≡ traverse (g . f)
* Naturality of sequencing: f . sequence = sequence . comap f
* Preserving point: p (point x) ≡ point x
* Preserving apply: f (x <*> y) ≡ f x <*> f y

Minimal complete definition

(->>)

Methods

(->>) :: (Pointable u, Applicative u) => t a -> (a -> u b) -> (u :.: t) b Source #

Infix version of traverse

traverse :: (Pointable u, Applicative u) => (a -> u b) -> t a -> (u :.: t) b Source #

Prefix version of ->>

sequence :: (Pointable u, Applicative u) => (t :.: u) a -> (u :.: t) a Source #

The dual of distribute

Instances

Traversable Identity Source #
Instance details Defined in Data.Functor.Identity Methods (->>) :: (Pointable u, Applicative u) => Identity a -> (a -> u b) -> (u :.: Identity) b Source # traverse :: (Pointable u, Applicative u) => (a -> u b) -> Identity a -> (u :.: Identity) b Source # sequence :: (Pointable u, Applicative u) => (Identity :.: u) a -> (u :.: Identity) a Source #
Traversable t => Traversable (Yoneda t) Source #
Instance details Defined in Data.Functor.Yoneda Methods (->>) :: (Pointable u, Applicative u) => Yoneda t a -> (a -> u b) -> (u :.: Yoneda t) b Source # traverse :: (Pointable u, Applicative u) => (a -> u b) -> Yoneda t a -> (u :.: Yoneda t) b Source # sequence :: (Pointable u, Applicative u) => (Yoneda t :.: u) a -> (u :.: Yoneda t) a Source #
Traversable (Constant a :: * -> *) Source #
Instance details Defined in Data.Functor.Constant Methods (->>) :: (Pointable u, Applicative u) => Constant a a0 -> (a0 -> u b) -> (u :.: Constant a) b Source # traverse :: (Pointable u, Applicative u) => (a0 -> u b) -> Constant a a0 -> (u :.: Constant a) b Source # sequence :: (Pointable u, Applicative u) => (Constant a :.: u) a0 -> (u :.: Constant a) a0 Source #