Classification (IS/AS)

Classification operators create properties that determine whether an object belongs to the class specified, which can be a user class or a built-in class. The value of the created property depends on whether the object belongs to that class:

Operator	Object belongs to the class	Object does not belong
IS	the logical value TRUE	NULL
AS	the object itself, of the class specified	NULL

Language

To implement classification operators, IS and AS operators are used.

Examples

asOrder(object) = object AS Order;

person = DATA Human (Order);
isMale (Order o) = person(o) IS Male;