An optional function that is called to initialize the Objective-C foreign object.
An optional Objective-C foreign object pointer for the object.
The abstract class standard-objc-object provides the framework for subclasses to implement an Objective-C class. Subclasses are typically defined using define-objc-class, which allows the Objective-C class name to be specified. Instances of such a subclass have an associated Objective-C foreign object whose pointer can be retrieved using the objc-object-pointer accessor. The function objc-object-from-pointer can be used to obtain the object again from the Objective-C foreign pointer.
There are two ways that subclasses of standard-objc-object can be made:
make-instance. In this case, the Objective-C object is allocated automatically by calling the Objective-C class's "alloc" method. If the init-function initarg is not specified, the object is initialized by calling its "init" method. If the init-function initarg is specified, it is called during initialization with the newly allocated object and it should call the appropriate initialization method for that object and return its result. This allows a specific initialization method, such as "initWithFrame:", to be called if required."allocWithZone:" method (or a method such as "alloc" that calls "allocWithZone:"). In this case, an instance of the subclass of standard-objc-object is made with the value of the pointer initarg being a pointer to the newly allocated Objective-C foreign object.LispWorks Objective-C and Cocoa Interface User Guide and Reference Manual - 21 Mar 2017