A Service Container in a Tweet

Container.php

<?php

/**
 * The Container class is a lightweight service container.
 *
 * ...and it fits in a tweet.
 *
 * @author Quentin Schuler aka Sukei <qschuler@neosyne.com>
 */
class Container{private $s;function set($k,$c){$this->s[$k]=$c;}function get($k){return(is_a($v=$this->s[$k],'Closure'))?$v($this):$v;}}

<?php

class Mailer
{
    private $transport;

    public function __construct($transport)
    {
        $this->transport = $transport;

        // ...
    }
}

<?php

class NewsletterManager
{
    private $mailer;

    public function __construct(Mailer $mailer)
    {
        $this->mailer = $mailer;

        // ...
    }
}

<?php

$container = new Container();

$container->set('mailer.class', 'Mailer');
$container->set('mailer.transport', 'sendmail');
$container->set('mailer', function(Container $container) {
    $class = $container->get('mailer.class');

    return new $class($container->get('mailer.transport'));
});

$container->set('newsletter_manager.class', 'NewsletterManager');
$container->set('newsletter_manager', function(Container $container) {
    $class = $container->get('newsletter_manager.class');

    return new $class($container->get('mailer'));
});

$manager = $container->get('newsletter_manager');