'object' is an object class. An object is a composite structure that contains internal state information, methods [which respond to messages], a pointer to the object's class and a pointer to the object's super-class. XLISP contains two built in objects: 'object' and class. 'object' is the superclass for the class object.
(send object :show) ; look at the object definition
; example use of objects
(setq my-class (send class :new '(state))) ; new class MY-CLASS with STATE
(send my-class :answer :isnew '() ; set up initialization
'((setq state nil) self))
(send my-class :answer :set-it '(value) ; create :SET-IT message
'((setq state value)))
(setq my-obj (send my-class :new)) ; create MY-OBJ out of MY-CLASS
(send my-obj :set-it 5) ; STATE is set to 5
Object definition: The internal definition of the 'object' object instance is:
Object is #<Object: #23fd8>, Class is #<Object: #23fe2>
MESSAGES = ((:SHOW . #<Subr-: #23db2>)
(:CLASS . #<Subr-: #23dee>)
(:ISNEW . #<Subr-: #23e2a>))
IVARS = NIL
CVARS = NIL
CVALS = NIL
SUPERCLASS = NIL
IVARCNT = 0
IVARTOTAL = 0
#<Object: #23fd8>
The class of 'object' is class. There is no superclass of 'object'. Remember that the location information [like #23fd8] varies from system to system, yours will probably look different.
Built-in methods: The built in methods in XLISP include:
Message structure: The normal XLISP convention for a 'message' is to have a valid symbol preceeded by a colon like :isnew or ':my-message'. However, it is possible to define a 'message' that is a symbol without a colon, but this makes the code less readable.
See the
object
class in the