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From: "B. Pym" <Nobody447095@here-nor-there.org>
Newsgroups: comp.lang.lisp
Subject: Re: Question about loop
Date: Mon, 26 Aug 2024 08:14:45 -0000 (UTC)
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Pascal Costanza wrote:

> Jeff Barnett wrote:
> > Does the Common Lisp spec say anything about whether the following is
> > well defined given that the elements of "list" are unique:
> >
> > (loop for x in list
> >   when (p x)
> >   do (setq list (delete x list)))
> 
> See http://www.lispworks.com/documentation/HyperSpec/Body/03_f.htm
> 
> But I wouldn't worry too much and just switch to a non-destructive version:
> 
> (loop for x in list
>        unless (p x) collect x into new-list
>        finally (setq list new-list))

Gauche Scheme:

(remove odd? (iota 22))
  ===>
(0 2 4 6 8 10 12 14 16 18 20)