Допис з розмови Newby(ish)

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From: Gregory Rickeard <s9905...@sms.ed.ac.uk>
Newsgroups: comp.lang.lisp
Subject: Re: Newby(ish)
Date: Tue, 15 Jul 2003 23:43:48 +0100
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On 27 Jun 2003, Joe Marshall wrote:

>
> Instead of RPLACA and RPLACD, you should use SETF
>
I was under the impression thet using SETF on elements of a list
would not alter the origional structure...

> (setf (car args) subst)  instead of   (rplaca args subst)
>
> and
>
> (setf (cadr args) subst) instead of (rplacd args (list subst))
>
This did not work when I tried the substitution, however
(setf (second args) subst) worked fine...

>
> You should consider representing the nodes in your tree as defstructs.
>

This unfortunataly did not solve the problem - looks like i will have to
re-implement the program using structures.

Thanks anyway.

Greg