fineui/src/polyfill/function.js

if (!Function.prototype.bind) {
    Function.prototype.bind = function(oThis) {
        if (typeof this !== 'function') {
            // closest thing possible to the ECMAScript 5
            // internal IsCallable function
            throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable');
        }

        var aArgs   = Array.prototype.slice.call(arguments, 1),
            fToBind = this,
            fNOP    = function() {},
            fBound  = function() {
                return fToBind.apply(this instanceof fNOP
                        ? this
                        : oThis,
                    // 获取调用时(fBound)的传参.bind 返回的函数入参往往是这么传递的
                    aArgs.concat(Array.prototype.slice.call(arguments)));
            };

        // 维护原型关系
        if (this.prototype) {
            // Function.prototype doesn't have a prototype property
            fNOP.prototype = this.prototype;
        }
        fBound.prototype = new fNOP();

        return fBound;
    };
}