function ToObject(val) {
    if (val == null) {
        throw new TypeError('Object.assign cannot be called with null or undefined');
    }

    return Object(val);
}
module.exports = Object.assign || function (target, source) {
    var from;
    var keys;
    var to = ToObject(target);

    for (var s = 1; s < arguments.length; s++) {
        from = arguments[s];
        keys = Object.keys(Object(from));

        for (var i = 0; i < keys.length; i++) {
            to[keys[i]] = from[keys[i]];
        }
    }

    return to;
};

//https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Array/slice
/**
* Shim for "fixing" IE's lack of support (IE < 9) for applying slice
* on host objects like NamedNodeMap, NodeList, and HTMLCollection
* (technically, since host objects have been implementation-dependent,
* at least before ES6, IE hasn't needed to work this way).
* Also works on strings, fixes IE < 9 to allow an explicit undefined
* for the 2nd argument (as in Firefox), and prevents errors when
* called on other DOM objects.
*/

var _slice = Array.prototype.slice
try {
    // Can't be used with DOM elements in IE < 9
    _slice.call(document.documentElement)
} catch (e) { // Fails in IE < 9
    // This will work for genuine arrays, array-like objects,
    // NamedNodeMap (attributes, entities, notations),
    // NodeList (e.g., getElementsByTagName), HTMLCollection (e.g., childNodes),
    // and will not fail on other DOM objects (as do DOM elements in IE < 9)
    Array.prototype.slice = function (begin, end) {
        // IE < 9 gets unhappy with an undefined end argument
        end = (typeof end !== 'undefined') ? end : this.length

        // For native Array objects, we use the native slice function
        if (Array.isArray(this) ) {
            return _slice.call(this, begin, end)
        }

        // For array like object we handle it ourselves.
        var i, cloned = [],
               size, len = this.length

        // Handle negative value for "begin"
        var start = begin || 0
        start = (start >= 0) ? start : len + start

        // Handle negative value for "end"
        var upTo = (end) ? end : len
        if (end < 0) {
           upTo = len + end
        }

        // Actual expected size of the slice
        size = upTo - start

        if (size > 0) {
            cloned = new Array(size)
            if (this.charAt) {
                for (i = 0; i < size; i++) {
                    cloned[i] = this.charAt(start + i)
                }
            } else {
                for (i = 0; i < size; i++) {
                    cloned[i] = this[start + i]
                }
            }
        }

        return cloned
    }
}

avalon.slice = function (nodes, start, end) {
    return _slice.call(nodes, start, end)
}

typeof null// "object"
typeof document.childNodes //safari "function"
typeof document.createElement('embed')//ff3-10 "function"
typeof document.createElement('object')//ff3-10 "function"
typeof document.createElement('applet')//ff3-10 "function"
typeof /\d/i //在实现了ecma262v4的浏览器返回 "function"
typeof window.alert //IE678 "object""
var iframe = document.createElement('iframe');
document.body.appendChild(iframe);
xArray = window.frames[window.frames.length - 1].Array;
var arr = new xArray(1, 2, 3); // [1,2,3]
arr instanceof Array; // false
arr.constructor === Array; // false

window.onload = function() {
    alert(window.constructor);// IE67 undefined
    alert(document.constructor);// IE67 undefined
    alert(document.body.constructor);// IE67 undefined
    alert((new ActiveXObject('Microsoft.XMLHTTP')).constructor);// IE6789 undefined
}
isNaN("aaa") //true

//jquery2.0
var class2type
// Populate the class2type map
jQuery.each("Boolean Number String Function Array Date RegExp Object Error".split(" "), function(i, name) {
    class2type[ "[object " + name + "]" ] = name.toLowerCase();
});

jQuery.type = function( obj ) {
    if ( obj == null ) {
        return String( obj );
    }
   // Support: Safari <= 5.1 (functionish RegExp)
    return typeof obj === "object" || typeof obj === "function" ?
            class2type[ core_toString.call(obj) ] || "object" :
            typeof obj;
}

avalon.isPlainObject = function(obj) {
    return typeof obj === "object" && Object.getPrototypeOf(obj) === Object.prototype
}

avalon.isWindow = function (obj) {
    if (!obj)
        return false
    // 利用IE6、IE7、IE8 window == document为true,document == window竟然为false的神奇特性
    // 标准浏览器及IE9、IE10等使用正则检测
    return obj == obj.document && obj.document != obj
}

var rwindow = /^\[object (?:Window|DOMWindow|global)\]$/
function isWindow(obj) {//现代浏览器使用这个实现
    return rwindow.test(toString.call(obj))
}

if (isWindow(window)) {
    avalon.isWindow = isWindow
}

//http://javascript.nwbox.com/IEContentLoaded/
//by Diego Perini 2007.10.5
function IEContentLoaded(w, fn) {
    var d = w.document, done = false,
            init = function() {
        if (!done) {//只执行一次
            done = true;
            fn();
        }
    };
    (function() {
        try {//在DOM未建完之前调用元素doScroll抛出错误
            d.documentElement.doScroll('left');
        } catch (e) {//延迟再试
            setTimeout(arguments.callee, 50);
            return;
        }
        init();//没有错误则执行用户回调
    })();
    // 如果用户是在domReady之后绑定这个函数，则立即执行它
    d.onreadystatechange = function() {
        if (d.readyState == 'complete') {
            d.onreadystatechange = null;
            init();
        }
    };
}

var readyList = [];
avalon.ready = function(fn) {
    if (readyList) {
        readyList.push(fn);
    } else {
        fn();
    }
}
var readyFn, ready = W3C ? "DOMContentLoaded" : "readystatechange";
function fireReady() {
    for (var i = 0, fn; fn = readyList[i++]; ) {
        fn();
    }
    readyList = null;
    fireReady = avalon.noop; //惰性函数，防止IE9二次调用_checkDeps
}

function doScrollCheck() {
    try { //IE下通过doScrollCheck检测DOM树是否建完
        html.doScroll("left");
        fireReady();
    } catch (e) {
        setTimeout(doScrollCheck);
    }
}

//在Firefox 3.6之前，不存在readyState属性
//http://www.cnblogs.com/rubylouvre/archive/2012/12/18/2822912.html
if (!DOC.readyState) {
    var readyState = DOC.readyState = DOC.body ? "complete" : "loading";
}
if (DOC.readyState === "complete") {
    fireReady(); //如果在domReady之外加载
} else {
    avalon.bind(DOC, ready, readyFn = function() {
        if (W3C || DOC.readyState === "complete") {
            fireReady();
            if (readyState) { //IE下不能改写DOC.readyState
                DOC.readyState = "complete";
            }
        }
    });
    if (html.doScroll) {
        try { //如果跨域会报错，那时肯定证明是存在两个窗口的
            if (self.eval === parent.eval) {
                doScrollCheck();
            }
        } catch (e) {
            doScrollCheck();
        }
    }
}