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Issue EQUALP-GENERIC
- To: gregor.pa@XEROX.COM
- Subject: Issue EQUALP-GENERIC
- From: Kim A. Barrett <IIM@ECLA.USC.EDU>
- Date: Sat 4 Mar 89 17:37:32-PST
- Cc: cl-cleanup@SAIL.STANFORD.EDU, iim@ECLA.USC.EDU
> Date: Wed, 1 Mar 89 19:50 PST
> From: Gregor.pa@Xerox.COM
>
> > An error is signaled on an attempt to add a method on any built-in class.
>
> ... I think the first is just covered by one of the principles outlined in
> chapter 3. ...
Yes. I haven't gotten Chapter 3 assimilated into my thinking yet.
> > Adding a method on a class after ALLOCATE-INSTANCE has been called on the
> > class has undefined consequences.
>
> {This} seems well intentioned but unreasonable. For one thing, some
> implementations may call allocate-instance before defclass returns. For
> another, it seems too painful to suggest that in order to define such a
> method you have to boot your lisp first. If this is really the only way the
> rest of the proposal can hold together, I think we need to reconsider the
> proposal.
I agree this is a serious weak point. Clearly, something needs to be said here
about the problem of breaking existing data structures by redefining the
functions they were built with. The restriction I wrote was intended mostly as
a place-holder while we try to come up with something better.
kab
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