generic-function

generic-function System Class

Class Precedence List:

generic-function, function, t

Description:

A generic function is a function whose behavior depends on the classes or identities of the arguments supplied to it. A generic function object contains a set of methods, a lambda list, a method combination type, and other information. The methods define the class-specific behavior and operations of the generic function; a method is said to specialize a generic function. When invoked, a generic function executes a subset of its methods based on the classes or identities of its arguments.

A generic function can be used in the same ways that an ordinary function can be used; specifically, a generic function can be used as an argument to funcall and apply, and can be given a global or a local name.

Expanded Reference: generic-function

The generic-function System Class

generic-function is the type of all generic function objects. Generic functions dispatch to methods based on the classes of their arguments.

(defgeneric area (shape))

(typep #'area 'generic-function)
=> T

(typep #'area 'function)
=> T

Ordinary Functions Are Not Generic

(typep #'car 'generic-function)
=> NIL