The an example of chain closure in php

chain_closure.php

//dilo surucu
class Step
{

    /**
     * @var Closure[] $steps
     */
    private array $steps;


    public function add(Closure $step): void
    {
        $this->steps[] = $step;
    }

    public function execute(mixed $data): mixed
    {
        if (empty($this->steps)) {
            return $data;
        }
        $next = function ($data) use (&$next) {
            $nextClosure=next($this->steps) ?: static fn($d, Closure $next)=>$d;
            return $nextClosure($data,$next);
        };
        $startClosure = reset($this->steps);
        return $startClosure($data, $next);

    }
}

$step = new Step();

$step->add(function (int $number, Closure $next) {
    return $next($number + 1);
});

$step->add(function (int $number, Closure $next) {
    return $next($number / 4);
});

$step->add(function (int $number,Closure $next) {
    return $next($number*2);
});

$step->add(function (int $number){
    return "the result of the step is $number";
});
echo $step->execute(7); //the result of the step is 4