4.2. Classes [sec_4-3]

The CLOS symbols are EXPORTed from the package CLOS. COMMON-LISP uses (as in USE-PACKAGE) CLOS and EXT:RE-EXPORTs the [ANSI CL standard] standard exported symbols (the CLISP extensions, e.g., those described in Chapter 29, Meta-Object Protocol, are not EXT:RE-EXPORTed). Since the default :USE argument to MAKE-PACKAGE is COMMON-LISP, the standard CLOS symbols are normally visible in all user-defined packages. If you do not want them (for example, if you want to use the PCL implementation of CLOS instead of the native one), do the following:

(DEFPACKAGE "CL-NO-CLOS" (:use "CL"))
(DO-EXTERNAL-SYMBOLS (symbol COMMON-LISP)
  (SHADOW symbol "CL-NO-CLOS"))
(DO-SYMBOLS (symbol "CL-NO-CLOS")
  (EXPORT symbol "CL-NO-CLOS"))
(IN-PACKAGE "CL-NO-CLOS")
(LOAD "pcl")or whatever
(DEFPACKAGE "MY-USER" (:use "CL-NO-CLOS"))
(IN-PACKAGE "MY-USER")
;; your code which uses PCL goes here

These notes document CLISP version 2.49.93+Last modified: 2018-02-19