Dmitry Mamontov has posted the second part of his "How to Create a PHP C Extension to Manipulate Arrays" series on PHPClasses, building on part one and adding in the ArrayAccess and Traversable interface functionality.

In the first part of this article we learned how to create an extension for PHP written in C to create a class that works like arrays. However, to make the class objects really behave as arrays you need to implement certain interfaces in the class.

Read this article to learn how to make a PHP class defined by a C extension implement ArrayAccess and Traversable interfaces, as well understand how to solve problems that you may encounter that can make your extension slower than you expect.

He takes the class he defined in part one and walks you through the addition of the two interfaces. He shows you where they're defined in the PHP source, what the code looks like and how they integrate with the class. He also shows you how to customize the object class handlers, making it possible to use the custom class (object) as an array. Adding Traversable is easier, adding an iterator return method that allows for the data internal to the class to be iterated through.