8. Predicates and Utilities Now that we know how to create
classes, access slots, and define methods, it might be useful to
verify that everything is doing ok. To help with this a plethora
of predicates have been created. - Function: class-v class -
Return a vector with all the class's important parts in it. This
vector is not a copy. Changing this vector changes the class.
The CLOS method find-class will have the same effect. -
Function: find-class symbol &optional errorp - CLOS function. In
EIEIO it returns the vector definition of the class. If there is
no class, nil is returned if errorp is - Function: class-p class
- Return non- nil if class is a class type. - Function: object-p
obj - Return non- nil if obj is an object. - Function: slot-
exists-p obj-or-class slot - Return Non- nil if obj-or-class
contains slot in its class. - Function: slot-boundp object slot
nil if OBJECT's SLOT is bound. Setting a slot's value makes it
bound. Calling slot-makeunbound will make a slot unbound. OBJECT
can be an instance