Re: Dynamically re-defining classes

[rich@linus.mitre.org]

>>    To: CommonLoops.pa@Xerox.COM
>>    Subject: Dynamically re-defining classes
>>    Date: Wed, 6 Sep 89 10:35 CDT
>>    From: rich@linus.MITRE.ORG
>>
>>    I know that there is probably some nifty CLOS functionality to do the
>>    following....
>>
>>    I want to define a class, and then later, without re-evaluating the
>>    defclass form, I want to change the class, i.e., add another
>>    slot.  Is there any easy way to do this?  I have thought of some
>>    involved ways, but I want to stay within the CLOS protocol.
>>
>>	    Rich
>
>Date: Tue, 19 Sep 89 17:47 CDT
>From: Nat Ballou <ballou@mcc.com>>
>Subject: RE: Dynamically re-defining classes
>To: rich@linus.mitre.org
>
>Hi,
>  Did you ever get a response to this message?  I am interested in any
>solutions you received?
>  Thanks,
>    Nat

>
>Date: Thu, 21 Sep 89 09:09 CDT
>From: Nat Ballou <ballou@ERNEST.ACA.MCC.COM>
>Subject: Re: Dynamically re-defining classes
>To: rich@linus.mitre.org
>
>If it's not too much code, would you mind telling how you did it in PCL?

I got side-tracked so I never actually coded it up.  I think
the best way to do it is by using the function/method UPDATE-CLASS.

Also, you could define a new metaclass that would have the right
behavior, but that would be a lot more hairy....

Good luck.