From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: bojohan+news@dd.chalmers.se (Johan =?utf-8?Q?Bockg=C3=A5rd?=) Newsgroups: gmane.emacs.devel Subject: Re: Strange change in backquote expansion Date: Sun, 19 Aug 2007 18:19:49 +0200 Message-ID: References: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: sea.gmane.org 1187540426 10757 80.91.229.12 (19 Aug 2007 16:20:26 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Sun, 19 Aug 2007 16:20:26 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Aug 19 18:20:22 2007 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1IMnVl-0000xr-Ks for ged-emacs-devel@m.gmane.org; Sun, 19 Aug 2007 18:20:21 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IMnVl-0000hV-3g for ged-emacs-devel@m.gmane.org; Sun, 19 Aug 2007 12:20:21 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IMnVh-0000fg-C8 for emacs-devel@gnu.org; Sun, 19 Aug 2007 12:20:17 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IMnVe-0000bm-QX for emacs-devel@gnu.org; Sun, 19 Aug 2007 12:20:17 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IMnVe-0000be-Nj for emacs-devel@gnu.org; Sun, 19 Aug 2007 12:20:14 -0400 Original-Received: from main.gmane.org ([80.91.229.2] helo=ciao.gmane.org) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1IMnVe-0001fK-Qk for emacs-devel@gnu.org; Sun, 19 Aug 2007 12:20:15 -0400 Original-Received: from list by ciao.gmane.org with local (Exim 4.43) id 1IMnVT-0003z7-IT for emacs-devel@gnu.org; Sun, 19 Aug 2007 18:20:03 +0200 Original-Received: from gamma02.me.chalmers.se ([129.16.50.72]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 19 Aug 2007 18:20:03 +0200 Original-Received: from bojohan+news by gamma02.me.chalmers.se with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 19 Aug 2007 18:20:03 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: emacs-devel@gnu.org Original-Lines: 39 Original-X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: gamma02.me.chalmers.se Mail-Copies-To: never User-Agent: Gnus/5.110007 (No Gnus v0.7) Emacs/22.1.50 (gnu/linux) Cancel-Lock: sha1:0tR1fGtHLNqytMjAie4pYHWmqxQ= X-Detected-Kernel: Linux 2.6, seldom 2.4 (older, 4) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:76764 Archived-At: Richard Stallman writes: > ``(,,@(list (list arg)))) > > I don't think that is a meaningful expression. ,@ is supposed to be > used inside of a list, to cause appending into that list. Using it > after a comma means it isn't in any visible list. $ sbcl This is SBCL 1.0, an implementation of ANSI Common Lisp. More information about SBCL is available at . SBCL is free software, provided as is, with absolutely no warranty. It is mostly in the public domain; some portions are provided under BSD-style licenses. See the CREDITS and COPYING files in the distribution for more information. * (defmacro debug-macro-test (arg) ``(,,@(list (list arg)))) DEBUG-MACRO-TEST * (macroexpand '(debug-macro-test foo)) `(,(FOO)) T * (debug-macro-test *) (1) So ,,@q means ``the value of q is a list of forms; splice the list of values of the elements of the value of q.'' [ Steele, Common Lisp the Language, 2nd edition, Appendix C. Backquote, http://www.cs.cmu.edu/Groups/AI/html/cltl/clm/node367.html ] -- Johan Bockgård