Asynchronous parallel - different approach

gistfile1.js

/* usage: 

  parallel(
    func1, [arg, arg, arg...],
    func2, [arg, arg, arg...],
    ...
    function() {
      arguments[0]; // holds output from first function
      arguments[1]; // holds output from second function
    }


    http://jsfiddle.net/8nF3g/
*/


parallel = function() {
    var onReady = arguments[arguments.length - 1];

    var ready = 0;
    var results = [];
    var count = (arguments.length - 1) / 2;

    for (var i = 0; i < arguments.length - 1; i += 2) {
        var func = arguments[i];
        var args = arguments[i + 1];

        var f = function foo() {
            var i = arguments[arguments.length - 1];
            results[foo.i / 2] = arguments;
            ready++;
            if (ready == count) {
                onReady.apply(null, results);
            }
        }

        f.i = i;

        args.push(f);

        func.apply(null, args)
    }
}