From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: pjb@informatimago.com (Pascal J. Bourguignon) Newsgroups: gmane.emacs.help Subject: Re: Adding Lists/Sequences Date: Fri, 26 Sep 2008 00:16:32 +0200 Organization: Informatimago Message-ID: <87abdv6fcv.fsf@hubble.informatimago.com> References: <3b97cca7-1c31-4e07-ba09-f0aeca96019c@34g2000hsh.googlegroups.com> <85r67apl6z.fsf@lola.goethe.zz> <87hc846bhn.fsf@lion.rapttech.com.au> <854p44new5.fsf@lola.goethe.zz> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1222382459 11470 80.91.229.12 (25 Sep 2008 22:40:59 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 25 Sep 2008 22:40:59 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Sep 26 00:41:56 2008 connect(): Connection refused Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1KizWt-0003vO-Ar for geh-help-gnu-emacs@m.gmane.org; Fri, 26 Sep 2008 00:41:47 +0200 Original-Received: from localhost ([127.0.0.1]:35175 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KizVr-0001pG-4E for geh-help-gnu-emacs@m.gmane.org; Thu, 25 Sep 2008 18:40:43 -0400 Original-Path: news.stanford.edu!newsfeed.stanford.edu!postnews.google.com!news4.google.com!proxad.net!feeder1-2.proxad.net!cleanfeed3-a.proxad.net!nnrp11-1.free.fr!not-for-mail Original-Newsgroups: gnu.emacs.help Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwAQMAAABtzGvEAAAABlBMVEUAAAD///+l2Z/dAAAA oElEQVR4nK3OsRHCMAwF0O8YQufUNIQRGIAja9CxSA55AxZgFO4coMgYrEDDQZWPIlNAjwq9 033pbOBPtbXuB6PKNBn5gZkhGa86Z4x2wE67O+06WxGD/HCOGR0deY3f9Ijwwt7rNGNf6Oac l/GuZTF1wFGKiYYHKSFAkjIo1b6sCYS1sVmFhhhahKQssRjRT90ITWUk6vvK3RsPGs+M1RuR mV+hO/VvFAAAAABJRU5ErkJggg== X-Accept-Language: fr, es, en X-Disabled: X-No-Archive: no Importance: high User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/22.2 (gnu/linux) Cancel-Lock: sha1:bm8aqDmSKkcLDWZW/3TRxKpDdzc= Original-Lines: 38 Original-NNTP-Posting-Date: 26 Sep 2008 00:16:33 MEST Original-NNTP-Posting-Host: 88.182.134.169 Original-X-Trace: 1222380993 news-4.free.fr 17310 88.182.134.169:45710 Original-X-Complaints-To: abuse@proxad.net Original-Xref: news.stanford.edu gnu.emacs.help:162749 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:58091 Archived-At: David Kastrup writes: > Tim X writes: > >> 1. Modifying 'literal' lists is usually risky. Weird things can happen >> because on some levels, you are modifying what is best considered a >> constant. > > That's all very vague and fuzzy, but there are no vague or fuzzy > semantics involved. Yes, there is vague and fuzzy semantics involved. The vagueness and fuzzyness is not very well characterised, because emacs lisp is not defined by a "standard", only by a (couple of) implementation(s). Nonetheless, nowhere can you see documented what the compiler does with literal objects. It could merge or duplicate them at will. Therefore self modifying code won't behave the same when interpreted and when compiled. >> This is the difference between '(1 2 3) and (list 1 2 3). > > The difference is that the first form is turned into a list by the Lisp > reader, each time it is passed through the reader (in most cases, once). > In interactive use, it is perfectly equivalent to the second form. When > put into function definitions or bound to anything, it isn't. Yes, another fuzzyness. -- __Pascal Bourguignon__ http://www.informatimago.com/ HANDLE WITH EXTREME CARE: This product contains minute electrically charged particles moving at velocities in excess of five hundred million miles per hour.