A question of style - Properties

i've just finished the "domain-specific" code for a Pear extension written in C, and im at the point of creating a user-land PHP extension for it. i wanted to get some consensus on properties, particularly those which trigger actions in the underlying library. to be more specific, what style do you prefer : a) $an_object->property = $some_value; echo $an_object->property; b) $an_object->setProperty($some_value); echo $an_object->getProperty(); i think it shouldnt matter for readonly properties, or those with no "side-effects", but what about other cases ? _____________________________________ "Fried Ice-Cream is a reality !" - George Clinton