From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.emacs.help Subject: Re: Mis-features of let Date: Tue, 19 Apr 2005 23:45:01 +0200 Organization: Organization?!? Message-ID: <85zmvuh25e.fsf@lola.goethe.zz> References: <1113844268.703229.310830@g14g2000cwa.googlegroups.com> <1113851147.155814.314630@g14g2000cwa.googlegroups.com> <87y8bfzx9z.fsf-monnier+gnu.emacs.help@gnu.org> <1113869741.838603.250620@o13g2000cwo.googlegroups.com> <87pswry5py.fsf-monnier+gnu.emacs.help@gnu.org> <1113882527.264397.292310@o13g2000cwo.googlegroups.com> <87y8bfwgrv.fsf-monnier+gnu.emacs.help@gnu.org> <1113892700.139927.168000@g14g2000cwa.googlegroups.com> <87hdi3vtxw.fsf-monnier+gnu.emacs.help@gnu.org> <1113942696.947385.229360@o13g2000cwo.googlegroups.com> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1113947216 14296 80.91.229.2 (19 Apr 2005 21:46:56 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 19 Apr 2005 21:46:56 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Apr 19 23:46:53 2005 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1DO0Xk-00014s-D4 for geh-help-gnu-emacs@m.gmane.org; Tue, 19 Apr 2005 23:46:04 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1DO0c8-0007ms-8y for geh-help-gnu-emacs@m.gmane.org; Tue, 19 Apr 2005 17:50:36 -0400 Original-Path: shelby.stanford.edu!newsfeed.stanford.edu!news.tele.dk!news.tele.dk!small.news.tele.dk!npeer.de.kpn-eurorings.net!newsfeed.arcor.de!news.arcor.de!not-for-mail Original-Newsgroups: gnu.emacs.help X-Face: 2FEFf>]>q>2iw=B6, xrUubRI>pR&Ml9=ao@P@i)L:\urd*t9M~y1^:+Y]'C0~{mAl`oQuAl \!3KEIp?*w`|bL5qr,H)LFO6Q=qx~iH4DN; i"; /yuIsqbLLCh/!U#X[S~(5eZ41to5f%E@'ELIi$t^ Vc\LWP@J5p^rst0+('>Er0=^1{]M9!p?&:\z]|;&=NP3AhB!B_bi^]Pfkw User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.50 (gnu/linux) Cancel-Lock: sha1:kQnREmmHRIIAXOH3Z/ksORktQcI= Original-Lines: 78 Original-NNTP-Posting-Date: 19 Apr 2005 23:45:13 MEST Original-NNTP-Posting-Host: 7f3b8599.newsread2.arcor-online.net Original-X-Trace: DXC=Z:=MIf; V\1NVg>C^g8i1FIQ5U85hF6f; DjW\KbG]kaMH:cmYYm_h3\CNA>:[`gB6>MQ1Yo0:e7@PKc[Wn>\JAZH@Ec?`[F:Wf@LM5Bockn`9XK Original-X-Complaints-To: abuse@arcor.de Original-Xref: shelby.stanford.edu gnu.emacs.help:130268 Original-To: help-gnu-emacs@gnu.org 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:25837 X-Report-Spam: http://spam.gmane.org/gmane.emacs.help:25837 "rgb" writes: > Now that I've slept, maybe I'll understand. Can we try again > > Stefan Monnier wrote: >> > If symbols created by let refer to an abstract concept then you're >> >> `let' does not create symbols. > > Ok, semantic error. From the point of view of a program the > symbol is being created and destroyed but actually it must > just be getting interned and uninterned. Uh, no. > I don't know of a way to tell the difference but I can't think of a > reason I'd need to know other than to use the correct term here. > > So if I conceed it isn't being `created' and you replace my > erroneous use of create with intern does it make any difference? > If not, what explains this? > > (defun test () > (let (foo) > (put 'foo 'hold "this ") > (symbol-plist 'foo))) > => test > > (unintern "foo") > => t > > (symbol-plist 'foo) > => nil > > (test) > => (hold "this ") > > (symbol-plist 'foo) > => nil > > The lifetime of the plist is obviously limited. Nonsense. How would you explain this then: (defun test () (let (foo) (put 'foo 'hold "this ") (setq woozle 'foo) (symbol-plist 'foo))) => test (unintern "foo") => t (symbol-plist 'foo) => nil (test) => (hold "this ") (symbol-plist 'foo) => nil (symbol-plist woozle) => (hold "this ") The symbol is obviously still there. It only is no longer associated with the same name. But as long as you took a snapshot of the symbol before it became anonymous (that's what woozle does), you can still refer to that snapshot, even though the symbol itself has no longer an accessible name. It does have a print name, though: woozle => foo Note that woozle is no longer the same as 'foo, since the association of the symbol stored in woozle with the default obarray does no longer exist. -- David Kastrup, Kriemhildstr. 15, 44793 Bochum