MiddlewareResolver.php

<?php

class MiddlewareResolver
{
    public $queue = [];

    public function __construct(array $list)
    {
        $this->queue = $list;
    }

    public function __invoke($a, $b):ResponseInterface
    {
        $_ = array_shift($this->queue);
        $_ = $_ ?? function($a, $b, $this){ return $b; };
        return $_->__invoke($a, $b, $this);
    }
}

class ResponseInterface
{
    // dummy
}

 $next2 = function($a, $b, $next){
    echo  "in next2".PHP_EOL;
    echo  "finish".PHP_EOL;
    $b = $next($a, $b);
    echo  "out next2".PHP_EOL;
    return $b;
};

$next1 = function($a, $b, $next) {
    echo  "in next".PHP_EOL;
    $b = $next($a, $b);
    echo  "out next".PHP_EOL;
    return $b;
};

$next = function($a, $b, $next){
    echo  "in b".PHP_EOL;
    $b = $next($a, $b);
    echo  "out b".PHP_EOL;
    return $b;
};

$seq = new MiddlewareResolver([
        $next,
        $next1,
        $next2,
]);

$seq(1,new ResponseInterface());