--- /dev/null
+'use strict';
+var $ = require('../internals/export');
+var IS_PURE = require('../internals/is-pure');
+var getBuiltIn = require('../internals/get-built-in');
+var anObject = require('../internals/an-object');
+var aFunction = require('../internals/a-function');
+var getIterator = require('../internals/get-iterator');
+var iterate = require('../internals/iterate');
+
+// `Set.prototype.isSubsetOf` method
+// https://tc39.github.io/proposal-set-methods/#Set.prototype.isSubsetOf
+$({ target: 'Set', proto: true, real: true, forced: IS_PURE }, {
+ isSubsetOf: function isSubsetOf(iterable) {
+ var iterator = getIterator(this);
+ var otherSet = anObject(iterable);
+ var hasCheck = otherSet.has;
+ if (typeof hasCheck != 'function') {
+ otherSet = new (getBuiltIn('Set'))(iterable);
+ hasCheck = aFunction(otherSet.has);
+ }
+ return !iterate(iterator, function (value, stop) {
+ if (hasCheck.call(otherSet, value) === false) return stop();
+ }, { IS_ITERATOR: true, INTERRUPTED: true }).stopped;
+ }
+});