1.4.1 Objects and pointers

When an Objective-C class is implemented in Lisp, each Objective-C foreign object has an associated Lisp object that can obtained by the function objc-object-from-pointer. Conversely, the function objc-object-pointer can be used to obtain a pointer to the foreign object from it associated Lisp object.

There are two kinds of Objective-C foreign object, classes and instances, each of which is associated with a Lisp object of some class as described in the following table:

Objective-C objects and associated Lisp objects

Objective-C type

FLI type descriptor

Class of associated Lisp object






subclass of standard-objc-object

The implementation of an Objective-C class in Lisp consists of a subclass of standard-objc-object and method definitions that become the Objective-C methods of the Objective-C class.

LispWorks Objective-C and Cocoa Interface User Guide and Reference Manual - 9 Mar 2006