node-query/node_modules/es6-shim/es6-sham.js
2014-11-25 14:23:08 -05:00

114 lines
3.7 KiB
JavaScript

/*!
* https://github.com/paulmillr/es6-shim
* @license es6-shim Copyright 2013-2014 by Paul Miller (http://paulmillr.com)
* and contributors, MIT License
* es6-sham: v0.20.2
* see https://github.com/paulmillr/es6-shim/blob/master/LICENSE
* Details and documentation:
* https://github.com/paulmillr/es6-shim/
*/
(function (undefined) {
'use strict';
/*jshint evil: true */
var getGlobal = new Function('return this;');
/*jshint evil: false */
var main = function () {
var globals = getGlobal();
var Object = globals.Object;
// NOTE: This versions needs object ownership
// beacuse every promoted object needs to be reassigned
// otherwise uncompatible browsers cannot work as expected
//
// NOTE: This might need es5-shim or polyfills upfront
// because it's based on ES5 API.
// (probably just an IE <= 8 problem)
//
// NOTE: nodejs is fine in version 0.8, 0.10, and future versions.
(function () {
if (Object.setPrototypeOf) { return; }
/*jshint proto: true */
// @author Andrea Giammarchi - @WebReflection
// define into target descriptors from source
var copyDescriptors = function (target, source) {
getOwnPropertyNames(source).forEach(function (key) {
defineProperty(
target,
key,
getOwnPropertyDescriptor(source, key)
);
});
return target;
};
// used as fallback when no promotion is possible
var createAndCopy = function (origin, proto) {
return copyDescriptors(create(proto), origin);
};
var create = Object.create;
var defineProperty = Object.defineProperty;
var getPrototypeOf = Object.getPrototypeOf;
var getOwnPropertyNames = Object.getOwnPropertyNames;
var getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
var proto = Object.prototype;
var set, setPrototypeOf;
try {
// this might fail for various reasons
// ignore if Chrome cought it at runtime
set = getOwnPropertyDescriptor(proto, '__proto__').set;
set.call({}, null);
// setter not poisoned, it can promote
// Firefox, Chrome
setPrototypeOf = function (origin, proto) {
set.call(origin, proto);
return origin;
};
} catch (e) {
// do one or more feature detections
set = {__proto__: null};
// if proto does not work, needs to fallback
// some Opera, Rhino, ducktape
if (set instanceof Object) {
setPrototypeOf = createAndCopy;
} else {
// verify if null objects are buggy
set.__proto__ = proto;
// if null objects are buggy
// nodejs 0.8 to 0.10
if (set instanceof Object) {
setPrototypeOf = function (origin, proto) {
// use such bug to promote
origin.__proto__ = proto;
return origin;
};
} else {
// try to use proto or fallback
// Safari, old Firefox, many others
setPrototypeOf = function (origin, proto) {
// if proto is not null
return getPrototypeOf(origin) ?
// use __proto__ to promote
((origin.__proto__ = proto), origin) :
// otherwise unable to promote: fallback
createAndCopy(origin, proto);
};
}
}
}
Object.setPrototypeOf = setPrototypeOf;
}());
};
if (typeof define === 'function' && define.amd) {
define(main); // RequireJS
} else {
main(); // CommonJS and <script>
}
}());