webdeveloper@webdevelopment ~/testing $ cat test_aclwhoswho.php 
<?php

require_once 'Zend/Acl.php';
require_once 'Zend/Acl/Role.php';
require_once 'Zend/Acl/Resource.php';

class HasIQFor implements Zend_Acl_Assert_Interface
{
    public function assert(Zend_Acl $acl, Zend_Acl_Role_Interface $role = null,
                           Zend_Acl_Resource_Interface $resource = null, $privilege = null)
    {
        echo "digging deeper";
        echo var_dump($role);
    }
}

class Acl_Child implements Zend_Acl_Role_Interface { public function getRoleId() { return 'Child'; } }
class Acl_Parent implements Zend_Acl_Role_Interface { public function getRoleId() { return 'Parent'; } }

$acl = new Zend_Acl();
$acl->addRole(new Zend_Acl_Role('Child'))
    ->addRole(new Zend_Acl_Role('Parent'), 'Child')
    ->add(new Zend_Acl_Resource('Toy'))
    ->add(new Zend_Acl_Resource('PokerGame'))
    ->allow('Child', 'Toy', 'Play', new HasIQFor())
    ->allow('Parent', 'PokerGame', 'Play', new HasIQFor());

$child = new Acl_Child();
$mommy = new Acl_Parent();

echo "Children and toys?\n"; echo $acl->isAllowed($child, 'Toy', 'Play');
echo "\n\nChildren and poker?\n"; echo $acl->isAllowed($child, 'PokerGame', 'Play');
echo "\n\nParents and toys?\n"; echo $acl->isAllowed($mommy, 'Toy', 'Play');
echo "\n\nParents and poker?\n"; echo $acl->isAllowed($mommy, 'PokerGame', 'Play');

webdeveloper@webdevelopment ~/testing $ php test_aclwhoswho.php 
Children and toys?
digging deeperobject(Zend_Acl_Role)#2 (1) {
  ["_roleId:protected"]=>
  string(5) "Child"
}


Children and poker?


Parents and toys?
digging deeperobject(Zend_Acl_Role)#2 (1) {
  ["_roleId:protected"]=>
  string(5) "Child"
}


Parents and poker?
digging deeperobject(Zend_Acl_Role)#4 (1) {
  ["_roleId:protected"]=>
  string(6) "Parent"
}