spl_autoload_register(function ($class) {
    $className = ltrim($class, '\\');
    if ($lastNsPos = strrpos($className, '\\')) {
        $namespace = substr($className, 0, $lastNsPos);
        $className = substr($className, $lastNsPos + 1);
    }

    if(strpos($class, $namespace) === 0) {
        if(strpos($namespace, DIRECTORY_SEPARATOR) !== false) {
            $folder = strtolower(substr($namespace, strpos($namespace, DIRECTORY_SEPARATOR) + 1));
            $path = str_replace('/', DIRECTORY_SEPARATOR, str_replace('\\', DIRECTORY_SEPARATOR, __DIR__ . '/' . $folder . '/' . $className . '.php'));
            if (is_file($path) && is_readable($path)) {
                include_once $path;
            }
        }
    }
});