traverse.js•1.16 kB
var _curry3 = require('./internal/_curry3');
var map = require('./map');
var sequence = require('./sequence');
/**
* Maps an [Applicative](https://github.com/fantasyland/fantasy-land#applicative)-returning
* function over a [Traversable](https://github.com/fantasyland/fantasy-land#traversable),
* then uses [`sequence`](#sequence) to transform the resulting Traversable of Applicative
* into an Applicative of Traversable.
*
* Dispatches to the `sequence` method of the third argument, if present.
*
* @func
* @memberOf R
* @since v0.19.0
* @category List
* @sig (Applicative f, Traversable t) => (a -> f a) -> (a -> f b) -> t a -> f (t b)
* @param {Function} of
* @param {Function} f
* @param {*} traversable
* @return {*}
* @see R.sequence
* @example
*
* // Returns `Nothing` if the given divisor is `0`
* safeDiv = n => d => d === 0 ? Nothing() : Just(n / d)
*
* R.traverse(Maybe.of, safeDiv(10), [2, 4, 5]); //=> Just([5, 2.5, 2])
* R.traverse(Maybe.of, safeDiv(10), [2, 0, 5]); //=> Nothing
*/
module.exports = _curry3(function traverse(of, f, traversable) {
return sequence(of, map(f, traversable));
});