ap.js•1.17 kB
var _concat = require('./internal/_concat');
var _curry2 = require('./internal/_curry2');
var _reduce = require('./internal/_reduce');
var curryN = require('./curryN');
var map = require('./map');
/**
* ap applies a list of functions to a list of values.
*
* Dispatches to the `ap` method of the second argument, if present. Also
* treats functions as applicatives.
*
* @func
* @memberOf R
* @since v0.3.0
* @category Function
* @sig [f] -> [a] -> [f a]
* @param {Array} fns An array of functions
* @param {Array} vs An array of values
* @return {Array} An array of results of applying each of `fns` to all of `vs` in turn.
* @example
*
* R.ap([R.multiply(2), R.add(3)], [1,2,3]); //=> [2, 4, 6, 4, 5, 6]
*/
module.exports = _curry2(function ap(applicative, fn) {
return (
typeof applicative.ap === 'function' ?
applicative.ap(fn) :
typeof applicative === 'function' ?
curryN(Math.max(applicative.length, fn.length), function() {
return applicative.apply(this, arguments)(fn.apply(this, arguments));
}) :
// else
_reduce(function(acc, f) { return _concat(acc, map(f, fn)); }, [], applicative)
);
});