函数柯里化

partially.js

// 摘自Secrets of the JavaScript Ninja
Function.prototype.partial = function() {
    var fn = this, args = Array.prototype.slice.call(arguments);
    return function() {
        var arg = 0;
        for (var i = 0; i < args.length && arg < arguments.length; i++) {
            if (args[i] === undefined) {
                args[i] = arguments[arg++];
            }
        }
        return fn.apply(this, args);
    };
};

var delay = setTimeout.partial(undefined, 10);
delay(function(){
    assert(true,
        "A call to this function will be delayed 10 ms.");
});