async js fn-queuing

aeach.js

async.each = function(toIterate, fn, callback){
    var calledCount = 0;
    for (var i = 0; i < toIterate.length; i++) {
        fn(toIterate[i], function(err){
            if(err){
                callback(err);
                callback = function(){};
                return;
            }
            calledCount++;
            if(calledCount >= toIterate.length){
                return callback();
            }
        }, i);
    }
};

amap.js

async.map = function(toMap, fn, callback){
    var mapped = [];
    async.each(toMap, function(obj, cb, i){
        fn(obj, function(err, ret){
            if(err){
                return cb(err);
            }
            mapped.push(ret);
            return cb();
        }, i);
    }, function(err){
        if(err){
            return callback(err);
        }
        return callback(null, mapped);
    });
};

aqueue.js

async.queue = function(){
    var queue = [];
    var me = {};
    
    me.queue = function(fn){
        queue.push(fn);
        return me;
    };
    me.exec = function(fn){
        var currentFn = 0;
        var runOne = function(data){
            queue[currentFn++](data, function(err, data){
                if(err || currentFn < queue.length - 1)  return fn(err, data);
                return runOne(data);
            });
        };
        return runOne();
    };
    
    return me;
}

/**
 * Use like this:
 * var q = async.queue();
 * q
 *  .queue(asyncTask1)
 *  .queue(function(fn){ setTimeout(function(){ fn(null, 'data') }, 500); })
 *  .queue(asyncTask3)
 *  .exec(function(err, data){ console.log(err, data); }));
 */