Re: OO and dynamic classes and methods...

From: Harvey J. Stein <hjstein_at_math.huji.ac.il>
Date: Fri, 3 Feb 1995 19:17:54 +0200

I don't think what Erick mentioned is exactly what is being looked
for.

Correct me if I'm wrong, Erick, but it seemed like you envisioned
people wanting to modify a class & have all the objects come along for
the ride.

As I understand it (which might be pretty far off, since I never
programmed in Self), the Self system isn't like this. I beleve Self
is somewhat like the class system in xlispstat. In some sense there
are no classes - just objects. Making an instance amounts to cloning
an existing object. For example, in xlispstat, there's a function
spin-plot which takes a list of coordinates as arguments and returns a
plot object. The plot object displays the points & allows one to
rotate them, etc. In xlispstat one can then take this plot object &
add methods and/or slots to it. This affects only this particular
instance, and no others. If you send this modified plot object the
'new message, you'll get a new instance of a plot object which will
also respond to the added methods & also have the added slots.

It's not clear to me how this would translate to STklos, since in CLOS
the objects don't really have methods - instead you have generic
functions.

None the less, I did enjoy these mutable objects that xlispstat has...

Dr. Harvey J. Stein
Berger Financial Research
hjstein_at_math.huji.ac.il
Received on Fri Feb 03 1995 - 18:19:36 CET