[Small-cl-src-discuss] Re: small mop compatability layer - small-cl-src-discuss@common-lisp.net - mailman3.common-lisp.net

1 Oct 2004


      marco mb@bese.it writes:
...
The mopp package also exports the function
SLOT-DEFINITION-DOCUMENTATION which while not strictly part of
the MOP really should be and is implementened on most systems.
It surprises me slightly that you think that
SLOT-DEFINITION-DOCUMENTATION shouldn't be a generic function.
...
IMPLEMENTATION - A keyword indetifying the implementation, one
of: :OPENMCL, :SBCL, :CMU, :LISPWORKS.
...
(let ((external-symbols '()))
  (do-external-symbols (sym (find-package :it.bese.arnesi.mopp))
    (push sym external-symbols))
  (dolist (sym external-symbols)
    (unless (provide-mopp-symbol sym #+openmcl :openmcl
                                     #+sbcl :sbcl
                                     #+cmu :cmu
                                     #+lispworks :lispworks)
      (warn "Unimplemented MOP symbol: ~S" sym))))
You could be slightly nicer to other implementations by doing
  ... (unless (provide-mopp-symbol sym (or #+openmcl :openmcl
                                           #+sbcl :sbcl
                                           #+cmu :cmu
                                           #+lispworks :lispworks
                                           :unimplemented))
        (warn ...))
and either provide a method on :unimplemented or a method on
NO-APPLICABLE-METHOD.
...
(defmethod provide-mopp-symbol ((symbol symbol)
                                (implementation (eql :sbcl)))
  (when (find-symbol (string symbol) :sb-pcl)
    (import-to-mopp (find-symbol (string symbol) :sb-pcl))))
Unless there's a reason not to, you should be using the "SB-MOP"
package here.  (If there is a reason, sbcl-devel wants to know about
it!)
Cheers,
Christophe