PHPWarrior\Abilities\Attack::perform PHP Method

    public function perform($direction = 'forward')
    {
        $direction = \PHPWarrior\Position::normalize_direction($direction);
        $this->verify_direction($direction);
        $receiver = $this->unit($direction);
        if ($receiver) {
            $this->unit->say(sprintf(__('attacks %1$s and hits %2$s'), __($direction), $receiver));
            if ($direction === 'backward') {
                $power = ceil($this->unit->attack_power() / 2.0);
            } else {
                $power = $this->unit->attack_power();
            }
            $this->damage($receiver, $power);
        } else {
            $this->unit->say(sprintf(__("attacks %s and hits nothing"), __($direction)));
        }
    }