debian-mirror-gitlab/core-js/modules/esnext.set.reduce.js
2019-09-25 13:30:05 +05:30

28 lines
1 KiB
JavaScript

'use strict';
var $ = require('../internals/export');
var IS_PURE = require('../internals/is-pure');
var anObject = require('../internals/an-object');
var aFunction = require('../internals/a-function');
var getSetIterator = require('../internals/get-set-iterator');
var iterate = require('../internals/iterate');
// `Set.prototype.reduce` method
// https://github.com/tc39/proposal-collection-methods
$({ target: 'Set', proto: true, real: true, forced: IS_PURE }, {
reduce: function reduce(callbackfn /* , initialValue */) {
var set = anObject(this);
var iterator = getSetIterator(set);
var accumulator, step;
aFunction(callbackfn);
if (arguments.length > 1) accumulator = arguments[1];
else {
step = iterator.next();
if (step.done) throw TypeError('Reduce of empty set with no initial value');
accumulator = step.value;
}
iterate(iterator, function (value) {
accumulator = callbackfn(accumulator, value, value, set);
}, undefined, false, true);
return accumulator;
}
});