--- /dev/null
+// https://github.com/tc39/proposal-iterator-helpers
+var $ = require('../internals/export');
+var path = require('../internals/path');
+var aFunction = require('../internals/a-function');
+var anObject = require('../internals/an-object');
+var toObject = require('../internals/to-object');
+var createIteratorProxy = require('../internals/iterator-create-proxy');
+var getIteratorMethod = require('../internals/get-iterator-method');
+
+var Iterator = path.Iterator;
+
+var IteratorProxy = createIteratorProxy(function (arg) {
+ var result = anObject(this.next.call(this.iterator, arg));
+ var done = this.done = !!result.done;
+ if (!done) return result.value;
+}, true);
+
+$({ target: 'Iterator', stat: true }, {
+ from: function from(O) {
+ var object = toObject(O);
+ var usingIterator = getIteratorMethod(object);
+ var iterator;
+ if (usingIterator != null) {
+ iterator = aFunction(usingIterator).call(object);
+ if (iterator instanceof Iterator) return iterator;
+ } else {
+ iterator = object;
+ } return new IteratorProxy({
+ iterator: iterator
+ });
+ }
+});