Module DA.Traversable

Class of data structures that can be traversed from left to right, performing an action on each element. You typically would want to import this module qualified to avoid clashes with functions defined in Prelude. Ie.:

import DA.Traversable   qualified as F

Typeclasses

class (Functor t, Foldable t) => Traversable t where

Functors representing data structures that can be traversed from left to right.

mapA

: Applicative f => (a -> f b) -> t a -> f (t b)

Map each element of a structure to an action, evaluate these actions from left to right, and collect the results.

sequence

: Applicative f => t (f a) -> f (t a)

Evaluate each action in the structure from left to right, and collect the results.

instance Ord k => Traversable (Map k)

instance Traversable TextMap

instance Traversable Optional

instance Traversable NonEmpty

instance Traversable (Validation err)

instance Traversable (Either a)

instance Traversable ([])

instance Traversable a

Functions

forA

: (Traversable t, Applicative f) => t a -> (a -> f b) -> f (t b)

forA is mapA with its arguments flipped.