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Re: Are "destructive" functions really destructive?
- To: slug@WARBUCKS.AI.SRI.COM
- Subject: Re: Are "destructive" functions really destructive?
- From: Richard Shu <rshu@ADS.COM>
- Date: Thu, 30 Nov 89 21:56:03 EST
- Distribution: usa
- Newsgroups: comp.lang.lisp, mail.info-slug
- Organization: Advanced Decision Systems, Mt. View, CA (415) 960-7300
- References: <email@example.com> <Nov.firstname.lastname@example.org> <25742E50.email@example.com> <31810@news.Think.COM>
- Reply-to: Richard Shu <rshu@ADS.COM>
- Sender: news@ADS.COM
In article <31810@news.Think.COM> firstname.lastname@example.org writes:
>If you want a DELETEF macro, create one. This would be just like the
>distinction between 1+ and INCF. If you think DELETEF should have been
>included in the standard language as INCF was, that's a completely
>different issue. I suspect it wasn't because then the language would have
>had to have SETF-like versions of all the destructive sequence operations.
>Maclisp and Zetalisp, the primary influences on Common Lisp, had INCF, so
>it was kept, but the CL designers apparently didn't want to throw in a
>zillion new macros of that type.
Yeah, but don't define DELETEF on a Symbolics or you'll redefine the
GLOBAL symbol DELETEF which is used to delete files! I did this once
a couple of years ago and spent several hours trying to figure out
why the system was acting so funny.
P.S. Barry also pointed out in another posting that I made the faulty
assumption that BACKQUOTE would create new lists. He's right. I goofed.
(responsible-p ADS message)