Lambda closures - substitution of use keyword

Hi there,

unfortunately the search doesn't work on the forums atm, so sorry if this question has already been asked...

I'm looking for a way to write something like this in Zephir:

    public function once($event, callable $listener)
    {
        $onceListener = function () use (&$onceListener, $event, $listener) {
            $this->removeListener($event, $onceListener);
            call_user_func_array($listener, func_get_args());
        };
        $this->on($event, $onceListener);
    }

(It's basically a Zephir port of igorw/evenement)

Any advice is welcome!