From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=) Newsgroups: gmane.lisp.guile.bugs Subject: bug#20087: gensym Date: Tue, 22 Mar 2016 08:58:27 +0100 Message-ID: <87wpovueos.fsf@gnu.org> References: <87a8zjxxpl.fsf@gnu.org> <87twjzytit.fsf@netris.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1458633570 10981 80.91.229.3 (22 Mar 2016 07:59:30 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 22 Mar 2016 07:59:30 +0000 (UTC) Cc: rain1@openmailbox.org, 20087@debbugs.gnu.org To: Mark H Weaver Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Tue Mar 22 08:59:14 2016 Return-path: Envelope-to: guile-bugs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1aiHDc-0006xb-Ov for guile-bugs@m.gmane.org; Tue, 22 Mar 2016 08:59:12 +0100 Original-Received: from localhost ([::1]:34329 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aiHDY-0008El-MN for guile-bugs@m.gmane.org; Tue, 22 Mar 2016 03:59:08 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53162) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aiHDV-0008Ef-MT for bug-guile@gnu.org; Tue, 22 Mar 2016 03:59:06 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aiHDS-0004wX-Gd for bug-guile@gnu.org; Tue, 22 Mar 2016 03:59:05 -0400 Original-Received: from debbugs.gnu.org ([208.118.235.43]:60539) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aiHDS-0004wL-Cz for bug-guile@gnu.org; Tue, 22 Mar 2016 03:59:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1aiHDS-0007r8-7r for bug-guile@gnu.org; Tue, 22 Mar 2016 03:59:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=) Original-Sender: "Debbugs-submit" Resent-CC: bug-guile@gnu.org Resent-Date: Tue, 22 Mar 2016 07:59:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 20087 X-GNU-PR-Package: guile X-GNU-PR-Keywords: Original-Received: via spool by 20087-submit@debbugs.gnu.org id=B20087.145863352030171 (code B ref 20087); Tue, 22 Mar 2016 07:59:02 +0000 Original-Received: (at 20087) by debbugs.gnu.org; 22 Mar 2016 07:58:40 +0000 Original-Received: from localhost ([127.0.0.1]:57666 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1aiHD6-0007qY-MD for submit@debbugs.gnu.org; Tue, 22 Mar 2016 03:58:40 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:33727) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1aiHD5-0007qM-K2 for 20087@debbugs.gnu.org; Tue, 22 Mar 2016 03:58:39 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aiHCx-0004kx-9W for 20087@debbugs.gnu.org; Tue, 22 Mar 2016 03:58:34 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:49046) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aiHCx-0004kt-5r; Tue, 22 Mar 2016 03:58:31 -0400 Original-Received: from pluto.bordeaux.inria.fr ([193.50.110.57]:60502 helo=pluto) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1aiHCw-0000Id-Fi; Tue, 22 Mar 2016 03:58:30 -0400 X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 3 Germinal an 224 de la =?UTF-8?Q?R=C3=A9volution?= X-PGP-Key-ID: 0x3D9AEBB5 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 3CE4 6455 8A84 FDC6 9DB4 0CFB 090B 1199 3D9A EBB5 X-OS: x86_64-unknown-linux-gnu In-Reply-To: <87twjzytit.fsf@netris.org> (Mark H. Weaver's message of "Tue, 22 Mar 2016 01:24:26 -0400") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 X-BeenThere: bug-guile@gnu.org List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Original-Sender: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.bugs:7993 Archived-At: Mark H Weaver skribis: > I've considered this idea in the past, but it only avoids collisions > with symbols that have been interned before the gensym. It does not > avoid collisions with symbols interned *after* the gensym. Obviously, > there's no way to avoid such collisions. Yeah, good point. > If we cannot eliminate the possibility of collisions, and we cannot > avoid intentional collisions, what can we do? I think the best we can > hope for is to significantly reduce the probability of _unintentional_ > collisions, perhaps by starting the gensym counter at a large number. I=E2=80=99m not sure if that would help. One thing that could help avoid unintentional collisions is to automatically add whitespace before the number, such that: (gensym "x") =3D> #{x 123}# (This is already the case when called with no arguments.) > The other thing we can do is to clearly document these inherent problems > with gensym, so that they will not be misused for jobs for which they > are not appropriate. I think we should add a sentence to that effect in the manual. Thanks, Ludo=E2=80=99.