From: Frederick C. Gibson, Architect
Subject: Question: Querying Class Hierarchies
Date: 
Message-ID: <7iuidu$gat@sjx-ixn10.ix.netcom.com>
I'm trying to find a way to extract class hierarchy info from class objects.
I've tried to do it using describe, but I can't seem to store the
information for further use.  Does anyone know a way to extract hierarchy
information such as direct-super and subclasses from a class object?

Thanks!

Fred Gibson, Architect

·········@gibson-design.com     Architecture Designed Objectively
==================================-----------||||||||||||||||||||||
Frederick Clifford Gibson Architect & Associates

     1220 14th Avenue Suite 106
     San Francisco, CA  94122
     415.753.3797 |tel|  415.759.8848 |fax|

     (c)1999 http://www.gibson-design.com

     EASG: Epistemology-Aesthetics Study Group
           http://www.gibson-design.com/philosophy
     ART:  American Renaissance for the Twenty-First Century
           http://www.art-21.org
From: Kenny Tilton
Subject: Re: Question: Querying Class Hierarchies
Date: 
Message-ID: <3752F3EB.ED0C75BD@liii.com>
What Lisp are you using? ACL offers #'class-direct-{super|sub}classes
from the Metaobject protocol. dependng on your Lisp's support of MOP,
you probably have something similar.

"Frederick C. Gibson, Architect" wrote:
> 
> I'm trying to find a way to extract class hierarchy info from class objects.
> I've tried to do it using describe, but I can't seem to store the
> information for further use.  Does anyone know a way to extract hierarchy
> information such as direct-super and subclasses from a class object?
> 
> Thanks!
> 
> Fred Gibson, Architect
> 
> ·········@gibson-design.com     Architecture Designed Objectively
> ==================================-----------||||||||||||||||||||||
> Frederick Clifford Gibson Architect & Associates
> 
>      1220 14th Avenue Suite 106
>      San Francisco, CA  94122
>      415.753.3797 |tel|  415.759.8848 |fax|
> 
>      (c)1999 http://www.gibson-design.com
> 
>      EASG: Epistemology-Aesthetics Study Group
>            http://www.gibson-design.com/philosophy
>      ART:  American Renaissance for the Twenty-First Century
>            http://www.art-21.org
From: Pierre R. Mai
Subject: Re: Question: Querying Class Hierarchies
Date: 
Message-ID: <87iu99kl8o.fsf@orion.dent.isdn.cs.tu-berlin.de>
Kenny Tilton <····@liii.com> writes:

> What Lisp are you using? ACL offers #'class-direct-{super|sub}classes
> from the Metaobject protocol. dependng on your Lisp's support of MOP,
> you probably have something similar.

Also, if the original poster finds out that his Lisp supports (some
parts) of the MOP, I'd recommend looking around for a hard-copy
of "The Art of the Meta-Object Protocol" by Gregor Kiczales et al.,
which IIRC includes just his problem as an example.

If no hard-copy is at hand, looking at the generic functions in
Chapters 5&6 (which are available online at the ALU web-site[1], and
provided by many vendors as part of their documentation), will
probably provide enough information...

Regs, Pierre.

Footnotes: 
[1]  http://www.elwood.com/alu/index.htm

-- 
Pierre Mai <····@acm.org>         PGP and GPG keys at your nearest Keyserver
  "One smaller motivation which, in part, stems from altruism is Microsoft-
   bashing." [Microsoft memo, see http://www.opensource.org/halloween1.html]
From: Tim Bradshaw
Subject: Re: Question: Querying Class Hierarchies
Date: 
Message-ID: <ey3hfor4ydc.fsf@lostwithiel.tfeb.org>
* Kenny Tilton wrote:
> What Lisp are you using? ACL offers #'class-direct-{super|sub}classes
> from the Metaobject protocol. dependng on your Lisp's support of MOP,
> you probably have something similar.

A trivial comment on this is that these things may well not be
accessible from the default package your Lisp starts in -- you might
have to do something like using the CLOS package (I don't know if
that's right for Allegro).

--tim
comp.lang.lisp / 1999 / may