serialq implementation - call functions sequentially for Node.js

serialq.js

exports.SerialQueue = function()
{
    var sq = 
    {
        funcs : [],
        next : function()
        {
            var Q = this;
            var f = Q.funcs.shift();
            if (f)
                f(function() {Q.next();});    
        },
        add : function(f)
        {
            this.funcs.push(f);
        },
        run : function()
        {
            this.next();
        }
    };
    return sq;
}

serialq_usage.js

var SerialQueue = require('serialq').SerialQueue;

{
    var Q = SerialQueue();

    Q.add(do_aaa);
    Q.add(do_bbb);
    Q.add(do_ccc);
    Q.add(function(next) { 
        console.log('\nall done\n'); 
        next();
    });

    Q.run();
}