A namespace based autoloader

autoloader.php

<?php

spl_autoload_register(function($class)
{
	$path = str_replace('\\', DIRECTORY_SEPARATOR, $class);

	// Convert the PascalCased names to snake_case
	$path = preg_replace('/([a-z])([A-Z](?![A-Z]))/', '$1_$2', $path);
	$path = strtolower($path);
	$path = LIB_PATH . '/' . $path . '.php';

	require($path);
});