// https://github.com/tc39/proposal-iterator-helpers
var $ = require('../internals/export');
-var path = require('../internals/path');
-var aFunction = require('../internals/a-function');
+var apply = require('../internals/function-apply');
var anObject = require('../internals/an-object');
var toObject = require('../internals/to-object');
+var isPrototypeOf = require('../internals/object-is-prototype-of');
+var AsyncIteratorPrototype = require('../internals/async-iterator-prototype');
var createAsyncIteratorProxy = require('../internals/async-iterator-create-proxy');
-var getAsyncIteratorMethod = require('../internals/get-async-iterator-method');
+var getAsyncIterator = require('../internals/get-async-iterator');
+var getIterator = require('../internals/get-iterator');
+var getIteratorMethod = require('../internals/get-iterator-method');
+var getMethod = require('../internals/get-method');
+var wellKnownSymbol = require('../internals/well-known-symbol');
+var AsyncFromSyncIterator = require('../internals/async-from-sync-iterator');
-var AsyncIterator = path.AsyncIterator;
+var ASYNC_ITERATOR = wellKnownSymbol('asyncIterator');
-var AsyncIteratorProxy = createAsyncIteratorProxy(function (arg) {
- return anObject(this.next.call(this.iterator, arg));
+var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise, args) {
+ return anObject(apply(this.next, this.iterator, args));
}, true);
$({ target: 'AsyncIterator', stat: true }, {
from: function from(O) {
var object = toObject(O);
- var usingIterator = getAsyncIteratorMethod(object);
+ var usingIterator = getMethod(object, ASYNC_ITERATOR);
var iterator;
- if (usingIterator != null) {
- iterator = aFunction(usingIterator).call(object);
- if (iterator instanceof AsyncIterator) return iterator;
- } else {
- iterator = object;
- } return new AsyncIteratorProxy({
- iterator: iterator
- });
+ if (usingIterator) {
+ iterator = getAsyncIterator(object, usingIterator);
+ if (isPrototypeOf(AsyncIteratorPrototype, iterator)) return iterator;
+ }
+ if (iterator === undefined) {
+ usingIterator = getIteratorMethod(object);
+ if (usingIterator) return new AsyncFromSyncIterator(getIterator(object, usingIterator));
+ }
+ return new AsyncIteratorProxy({ iterator: iterator !== undefined ? iterator : object });
}
});