Subject: Re: Two Questions
From: Erik Naggum <erik@naggum.net>
Date: 16 Dec 2000 15:11:01 +0000
Newsgroups: comp.lang.lisp
Message-ID: <3185968261469225@naggum.net>

* SRS <srs43@my-deja.com>
| Firstly, why is the function last not an accessor?

  Because (setf (last x n)) == (setf (cdr (last x (1+ n)))) in the specific
  case where you can modify the cdr of the cons pointing to the last cons
  because (last x n) is different from (last x (1+ n)).  When they return
  the same value, you have a problem.

  Besides, you aren't asking for last, but rest or cdr and both of those
  are certainly accessors in the language.  Maybe they aren't in your
  implementation, but if so, that's a reportable non-conformance bug.

#:Erik
-- 
  The United States of America, soon a Bush league world power.  Yeee-haw!