Michiel meghuizen

This article has been given a more permanent home on my blog. Also, since it was first written, the development of the Promises/A+ specification has made the original emphasis on Promises/A seem somewhat outdated.

You're Missing the Point of Promises

Promises are a software abstraction that makes working with asynchronous operations much more pleasant. In the most basic definition, your code will move from continuation-passing style:

getTweetsFor("domenic", function (err, results) {
 // the rest of your code goes here.

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

So you're curious in learning this new thing called (Functional) Reactive Programming (FRP).

Learning it is hard, even harder by the lack of good material. When I started, I tried looking for tutorials. I found only a handful of practical guides, but they just scratched the surface and never tackled the challenge of building the whole architecture around it. Library documentations often don't help when you're trying to understand some function. I mean, honestly, look at this:

Rx.Observable.prototype.flatMapLatest(selector, [thisArg])

Projects each element of an observable sequence into a new sequence of observable sequences by incorporating the element's index and then transforms an observable sequence of observable sequences into an observable sequence producing values only from the most recent observable sequence.

	<?php

	mt_srand(1361152757.2);

	for ($i=1; $i < 25; $i++) {
	echo mt_rand(), PHP_EOL;
	}

	<?php

	/**
	* SplClassLoader implementation that implements the technical interoperability
	* standards for PHP 5.3 namespaces and class names.
	*
	* http://groups.google.com/group/php-standards/web/final-proposal
	*
	* // Example which loads classes for the Doctrine Common package in the
	* // Doctrine\Common namespace.