A Tweet Sized Queue System

The Code

This is the 138 bytes version:


function Queue(args, f) {
  setTimeout(args.next = function next() {
    return (f = args.shift()) ? !!f(args) || !0 : !1;
  }, 0);
  return args;
}

While this is the 96 one:


function Queue(a,b){setTimeout(a.next=function(){return(b=a.shift())?!!b(a)||!0:!1},0);return a}

The Why

In almost every QCon London talk I have heard the word asynchronous. Well, the aim of the tweet sized function I have just written above is to make things easier.
After I have implemented builder/JSBuilder.js for wru, so that Python is not needed anymore to build the tiny library, I needed to make builder/build.js usable in a way that asynchronous calls through node won't bother, at least visually, the normal flow of the script.
After that I have thought: "why not making a generic Queue function with Promises like approach" ?

The What

It's quite straight forward, you create a queue, you use the queue. You might eventually pollute the queue or change its order, since the queue is nothing different from a generic Array with an extra method on it: next().
Here a basic example:


Queue([
  function (queue) {
    // do amazing stuff asynchronously
    setTimeout(function () {
      queue.message = "Hello Queue";
      queue.next();
    }, 500);
  },
  function (queue) {
    // do something else
    alert(queue.message);
    // Hello Queue
    queue.next(); // not necessary at the end
    // does not hurt thought 
  }
]);

That's Pretty Much It

So, the queue argument is the array created initially to define the ordered list of function.
This means you can recycle this variable even adding custom properties but most important is that you can change the queue via Array.prototype.splice/unshift/pop/push() methods and decide the future or the next function to execute runtime, if needed.
The only extra bit is about returning true or false in case there was a next() to execute or not.

Last, but not least, of course you can create new Queue([]) inside queues ... so, this is actually more powerful than many other queue systems I have seen so far and ... hey, 96 bytes: enjoy!

modisposition