An Middleware Builder in a tweet

middleware.php

<?php
// Minified
// class B{function __construct($m){$this->m = $m;} function __invoke($req,$res) {if($this->m)return array_shift($this->m)($req,$res,$this);}}

class B{
    function __construct($m)
    {
        $this->m = $m;
    }

    function __invoke($req,$res)
    {
        if($this->m)return array_shift($this->m)($req,$res,$this);
    }
}

require_once __DIR__.'/vendor/autoload.php';

$sender = function($q, $s, $n) {
    $s = $n($q, $s);
    echo $s->getBody();
    return $s;
};

$middlewarex = function($q, $s, $n) {
    $s->getBody()->write('Hello1');
    $s = $n($q, $s);
    $s->getBody()->write('Hello2');
    return $s;
};

$app = function($q, $s, $n) {
    $s->getBody()->write('APP');
    return $s;
};

$req = Zend\Diactoros\ServerRequestFactory::fromGlobals($_SERVER, $_GET, $_POST, $_COOKIE, $_FILES);
$res = new Zend\Diactoros\Response;

(new B([$sender, $middlewarex, $app]))($req,$res); // Hello1APPHello2