[MUD-Dev] Re: A Small Conceptual Object System For MUDs

[Ola Fosheim Grøstad <olag#ifi,uio.no>]

Emil Eifrem wrote:

> At 05:44 PM 11/6/98 , Ola Fosheim Grøstad wrote:
> >I'm striving for a model with few, but meaningful, classes and single
> >inheritance.

> My concern with this approach has to do with the single inheritance
> requirement.  As one of your goals is to "describe the most common MUDs," I
> think single inheritance with this model can cause problems.  I know many
> muds out there have banana-keys, flowers that are also wands and edible
> chairs.  How will you model this without multiple inheritance?

> An easy answer can be that you don't wish to go into such great detail,
> another could be to change the requirements.

Yes. This was a response to Jon Lambert's comment on the difficulty of finding a
common object model. I belive one should be able to come down to a common object
model at least on the conceptual level. Maybe you will have to add additional
constructs below the Item level during implementation to support your
Banana-key. Still, I think the main challenge is to find some base classes which
would be acceptable to almost all muds and then find out the most common
relationships. My preference for single inheritance is motivated by a desire to
force myself (and others) to think about (or rather rethink) the main
relationships. It is also motivated by a general dislike for the problems
associated with multiple inheritance. Of course, your comment does suggest that
the common object model will have to be fairly abstract in order to remain
useful for the general mud developer.

> ii) A fixed single-inheritance hierarchy. Consequences: Clean and neat
> world object hierarchy with minimal code duplication, but with an inability
> to support my trendy Banana-Keys. And everyone knows that all respectable
> muds either have or want them.

An alternative is to reflect the most important and used aspect in the
single-inheritance hierarchy. Then leave the more rare special cases to other
constructs (I believe this is what Mark Gritter suggested?)

Now, the real issue I was trying to get discussed was: How much can you stuff
into the LEVEL 0 in my object model without severely hampering the artistic
freedom of the designer? And what is really the "true" basic concepts found in
MUDs? Are the _basic_ conceptual relationships the same in most MUDs?
--
Ola