Extendable scopes

I’d like to have the possibility to build scopes inheriting from other scopes e.g.




public function scopes()

{

    return array(

        'visible' => array(

            'condition' => '`t`.`is_visible` = :visible',

            'params' => array(':visible' => true)

        ),

        'active' => array(

            'condition' => '`t`.`is_active` = :active',

            'params' => array(':active' => true)

        ),

        'public' => array(

            'visible',

            'active'

        ),

    );

}



me either :)