From mboxrd@z Thu Jan  1 00:00:00 1970
Path: main.gmane.org!not-for-mail
From: storm@cua.dk (Kim F. Storm)
Newsgroups: gmane.emacs.devel
Subject: let vs. buffer local bindings
Date: 10 May 2002 16:21:07 +0200
Sender: emacs-devel-admin@gnu.org
Message-ID: <5xy9esxewc.fsf@kfs2.cua.dk>
NNTP-Posting-Host: localhost.gmane.org
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Trace: main.gmane.org 1021036911 7774 127.0.0.1 (10 May 2002 13:21:51 GMT)
X-Complaints-To: usenet@main.gmane.org
NNTP-Posting-Date: Fri, 10 May 2002 13:21:51 +0000 (UTC)
Cc: Dave Pearson <davep.news@davep.org>,
        Gareth Owen <usenet@gwowen.freeserve.co.uk>
Return-path: <emacs-devel-admin@gnu.org>
Original-Received: from quimby.gnus.org ([80.91.224.244])
	by main.gmane.org with esmtp (Exim 3.33 #1 (Debian))
	id 176ALH-00021H-00
	for <emacs-devel@main.gmane.org>; Fri, 10 May 2002 15:21:51 +0200
Original-Received: from fencepost.gnu.org ([199.232.76.164])
	by quimby.gnus.org with esmtp (Exim 3.12 #1 (Debian))
	id 176AUO-0001sT-00
	for <emacs-devel@quimby.gnus.org>; Fri, 10 May 2002 15:31:16 +0200
Original-Received: from localhost ([127.0.0.1] helo=fencepost.gnu.org)
	by fencepost.gnu.org with esmtp (Exim 3.34 #1 (Debian))
	id 176AL3-00007R-00; Fri, 10 May 2002 09:21:37 -0400
Original-Received: from fepd.post.tele.dk ([195.41.46.149])
	by fencepost.gnu.org with smtp (Exim 3.34 #1 (Debian))
	id 176AJq-0008UF-00
	for <emacs-devel@gnu.org>; Fri, 10 May 2002 09:20:22 -0400
Original-Received: from kfs2.cua.dk.cua.dk ([194.239.225.46]) by fepD.post.tele.dk
          (InterMail vM.4.01.03.23 201-229-121-123-20010418) with SMTP
          id <20020510132021.UNQN7393.fepD.post.tele.dk@kfs2.cua.dk.cua.dk>;
          Fri, 10 May 2002 15:20:21 +0200
Original-To: emacs-devel@gnu.org
Original-Lines: 43
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2.50
Errors-To: emacs-devel-admin@gnu.org
X-BeenThere: emacs-devel@gnu.org
X-Mailman-Version: 2.0.9
Precedence: bulk
List-Help: <mailto:emacs-devel-request@gnu.org?subject=help>
List-Post: <mailto:emacs-devel@gnu.org>
List-Subscribe: <http://mail.gnu.org/mailman/listinfo/emacs-devel>,
	<mailto:emacs-devel-request@gnu.org?subject=subscribe>
List-Id: Emacs development discussions. <emacs-devel.gnu.org>
List-Unsubscribe: <http://mail.gnu.org/mailman/listinfo/emacs-devel>,
	<mailto:emacs-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <http://mail.gnu.org/pipermail/emacs-devel/>
Xref: main.gmane.org gmane.emacs.devel:3806
X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:3806


Gareth Owen <usenet@gwowen.freeserve.co.uk> has found a peculiar
interference between let and buffer local bindings.

Does anyone care to comment on the following result:

First try evalling:

(progn
  (make-variable-buffer-local 'foo)
  (setq-default foo 1)
  (list foo
	(let ((foo 2) (buf (generate-new-buffer "baz")))
	  (set-buffer buf) foo)
	(let ((foo 3) (buf (generate-new-buffer "baz")))
	  (set-buffer buf) foo)
	(let ((foo 4) (buf (generate-new-buffer "baz")))
	  (set-buffer buf) foo)))

which produces what seems to be correct:

  (1 2 3 4)


But now eval this:

(progn
  (setq foo 0)
  (list foo
	(let ((foo 2) (buf (generate-new-buffer "baz")))
	  (set-buffer buf) foo)
	(let ((foo 3) (buf (generate-new-buffer "baz")))
	  (set-buffer buf) foo)
	(let ((foo 4) (buf (generate-new-buffer "baz")))
	  (set-buffer buf) foo)))

which produces what seems to be wrong:

  (0 1 3 4)


-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk