Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!haven!mimsy!tove.umd.edu!folta
From: folta@tove.umd.edu (Wayne Folta)
Newsgroups: comp.lang.lisp
Subject: CLOS: is it OOP?
Message-ID: <19582@mimsy.UUCP>
Date: 14 Sep 89 00:21:12 GMT
Sender: nobody@mimsy.UUCP
Reply-To: folta@tove.umd.edu.UUCP (Wayne Folta)
Distribution: usa
Organization: U of Maryland, Dept. of Computer Science,gs
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I just got Allegro Common Lisp for my Mac, and I have a question concerning
CL's proposed object-oriented extension, CLOS.  I have been reading a book
which implies that CLOS can be argued to not be OO:

"Because CLOS makes no effort at protection or encapsulation, some might
find that it lacks the most essential thing for an object-oriented system."

"Generic functions are a step away from the concept of active data and back
toward the conventional division between passive data and active process."

Of course, the author has wonderful things to say about CLOS as well, and
praises its generic-function approach as one of Lisp's great contributions.

This could start firestorm here, but I don't completely understand OOPS,
and it would be nice to know what experts think about CLOS's OOP-edness.
(Apple's CL has Object Lisp extensions, and I have ordered Xerox's
CommonLOOPS, both of which I understand to be more traditionally "OOP-like"
than CLOS.)


Wayne Folta          (folta@tove.umd.edu  128.8.128.42)