differenceWith.js•1.23 kB
var _containsWith = require('./internal/_containsWith');
var _curry3 = require('./internal/_curry3');
/**
* Finds the set (i.e. no duplicates) of all elements in the first list not
* contained in the second list. Duplication is determined according to the
* value returned by applying the supplied predicate to two list elements.
*
* @func
* @memberOf R
* @since v0.1.0
* @category Relation
* @sig (a -> a -> Boolean) -> [*] -> [*] -> [*]
* @param {Function} pred A predicate used to test whether two items are equal.
* @param {Array} list1 The first list.
* @param {Array} list2 The second list.
* @return {Array} The elements in `list1` that are not in `list2`.
* @see R.difference
* @example
*
* var cmp = (x, y) => x.a === y.a;
* var l1 = [{a: 1}, {a: 2}, {a: 3}];
* var l2 = [{a: 3}, {a: 4}];
* R.differenceWith(cmp, l1, l2); //=> [{a: 1}, {a: 2}]
*/
module.exports = _curry3(function differenceWith(pred, first, second) {
var out = [];
var idx = 0;
var firstLen = first.length;
while (idx < firstLen) {
if (!_containsWith(pred, first[idx], second) &&
!_containsWith(pred, first[idx], out)) {
out.push(first[idx]);
}
idx += 1;
}
return out;
});