michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: module.metadata = {
michael@0:   "stability": "experimental"
michael@0: };
michael@0: 
michael@0: const method = require("../../method/core");
michael@0: const { Class } = require("./heritage");
michael@0: 
michael@0: // Object that inherit or mix WeakRefence inn will register
michael@0: // weak observes for system notifications.
michael@0: const WeakReference = Class({});
michael@0: exports.WeakReference = WeakReference;
michael@0: 
michael@0: 
michael@0: // If `isWeak(object)` is `true` observer installed
michael@0: // for such `object` will be weak, meaning that it will
michael@0: // be GC-ed if nothing else but observer is observing it.
michael@0: // By default everything except `WeakReference` will return
michael@0: // `false`.
michael@0: const isWeak = method("reference/weak?");
michael@0: exports.isWeak = isWeak;
michael@0: 
michael@0: isWeak.define(Object, _ => false);
michael@0: isWeak.define(WeakReference, _ => true);