The macro call-method is used in method combination. It hides
the implementation-dependent details of how
methods are called. The
macro call-method has lexical scope and
can only be used within
an effective method form.
Whether or not call-method is fbound in the
global environment is implementation-dependent;
however, the restrictions on redefinition and shadowing of
call-method are the same as for symbols in the common-lisp package
which are fbound in the global environment.
The consequences of attempting to use call-method outside
of an effective method form are undefined.
The macro call-method invokes the specified method,
supplying it with arguments and with definitions for
call-next-method and for next-method-p.
If the invocation of call-method is lexically inside
of a make-method, the arguments are those that
were supplied to that method. Otherwise the arguments are
those that were supplied to the generic function.
of call-next-method and next-method-p rely on
the specified next-method-list.
If method is a list, the first element of the list
must be the symbol make-method and the second element must be
a form. Such a list specifies a method object
whose method function has a body that is the given form.
Next-method-list can contain method objects or lists,
the first element of which must be the symbol make-method and the
second element of which must be a form.
Those are the only two places where make-method can be used.
The form used with make-method is evaluated in
the null lexical environment augmented with a local macro definition
for call-method and with bindings named by
symbols not accessible from the common-lisp-user package.
The call-next-method function available to method
will call the first method in next-method-list.
The call-next-method function
available in that method, in turn, will call the second
method in next-method-list, and so on, until
the list of next methods is exhausted.
If next-method-list is not supplied, the
call-next-method function available to
method signals an error of type control-error
and the next-method-p function
available to method returns nil.