A class is naturally also a set that contains all its members.
When the class is created, it is an empty set until the constructor is called
and a member is added to the set.
As a set, a class can be used as the domain of a function parameter, argument,
or a class member.
For example,
>> Dog = class
.....
.....
end
>> Spot = Dog.new();
>> Spot in Dog // check if Spot is a member of the dog class
1
>> Person = class
...
public dog in Dog;
...
end
Here a member of the Person class has an
attribute dog, which has to be a member of the
Dog class.
oz
2009-12-22