chickadee » coops » define-primitive-class

(define-primitive-class NAME [(SUPERCLASS ...)] PREDICATE)syntax

Defines a primitive class with the name NAME and the given list of superclasses. If no superclasses are specified, then the superclass list defaults to (<primitive-object>). PREDICATE should be a procedure of one argument determining whether the argument is a member of the newly defined primitive class.

The predicate should be referentially transparent.