call-next-fwrapper

Arguments:

Wherever placed in an fwrapper, this form results in a call made to the next more inner fwrapper on the primary-function being wrapped. If this fwrapper is the innermost fwrapper, then the primary function is called instead.

The arguments passed to the next more inner fwrapper (or primary function) are the current arguments as the function was originally called, modified by any storing forms in fwrappers which have already executed. Storing forms might be a setq of a required, optional, or keyword argument, or it may be a (setf nth) on any element of the &rest list. The presence or absence of Keyword arguments cannot be changed.

The form returns the value(s) returned by the next more inner fwrapper (or by the primary function, if this is the innermost fwrapper). It is the responsibility of each fwrapper to propagate return values as expected, or to substitute new return values to be returned. A standard construct for returning values untouched from within an fwrapper is

 (multiple-value-prog1
   (call-next-fwrapper)
  ;; Do some more stuff here
  ...
 )

See fwrappers-and-advice.htm for information of fwrapping functions (and on the older, deprecated advice facility).

Copyright (c) 1998-2016, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.1 page.
Created 2010.1.21.