精简的javascript下throttle和debounce代码

//频率控制 函数连续调用时，fn 执行频率限定为 1次/waitMs。立即执行
function throttle(waitMs, fn) {
    var lastRun = 0;
    return function () {
        var now = +new Date;
        if (now - lastRun > waitMs) {
            lastRun = now;
            fn.apply(null, arguments);
        }
    }
}

//空闲控制 返回函数连续调用时，空闲时间必须大于或等于 waitMs，fn 才会执行。延迟执行
function debounce(waitMs, fn) {
    var lastCall, args, timeout;
    return function r() {
        lastCall = +new Date;
        args = arguments;
        if (!timeout) {
            timeout = setTimeout(later, waitMs);
        }
    };

    function later() {
        var past = +new Date - lastCall;
        if (past > waitMs) {
            timeout = null;
            fn.apply(null, args)
        }
        else {
            timeout = setTimeout(later, waitMs - past + 1)
        }
    }
}

调用方法如下：

$(window).resize(debounce(100, function(evt){
    ......
}));

$(document).mousemove(throttle(40, function(evt){
    ......
}));