autoload.php

<?php

declare(strict_types=1);

/**
 * PSR-4 autoloader implementation for the MaxMind\DB namespace.
 * First we define the 'mmdb_autoload' function, and then we register
 * it with 'spl_autoload_register' so that PHP knows to use it.
 *
 * @param mixed $class
 */

/**
 * Automatically include the file that defines <code>class</code>.
 *
 * @param string $class
 *                      the name of the class to load
 */
function mmdb_autoload($class): void
{
    /*
    * A project-specific mapping between the namespaces and where
    * they're located. By convention, we include the trailing
    * slashes. The one-element array here simply makes things easy
    * to extend in the future if (for example) the test classes
    * begin to use one another.
    */
    $namespace_map = ['MaxMind\\Db\\' => __DIR__ . '/src/MaxMind/Db/'];

    foreach ($namespace_map as $prefix => $dir) {
        // First swap out the namespace prefix with a directory...
        $path = str_replace($prefix, $dir, $class);

        // replace the namespace separator with a directory separator...
        $path = str_replace('\\', '/', $path);

        // and finally, add the PHP file extension to the result.
        $path .= '.php';

        // $path should now contain the path to a PHP file defining $class
        if (file_exists($path)) {
            include $path;
        }
    }
}

spl_autoload_register('mmdb_autoload');