From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "rgb" Newsgroups: gmane.emacs.help Subject: Re: Mis-features of let Date: 19 Apr 2005 18:04:40 -0700 Organization: http://groups.google.com Message-ID: <1113959080.090388.307740@f14g2000cwb.googlegroups.com> 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> <1113945021.435672.62370@f14g2000cwb.googlegroups.com> <85sm1mh1f6.fsf@lola.goethe.zz> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Trace: sea.gmane.org 1113959167 10537 80.91.229.2 (20 Apr 2005 01:06:07 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Wed, 20 Apr 2005 01:06:07 +0000 (UTC) Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Apr 20 03:06:05 2005 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1DO3f0-0004Tj-H9 for geh-help-gnu-emacs@m.gmane.org; Wed, 20 Apr 2005 03:05:46 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1DO3jQ-0003Qs-4c for geh-help-gnu-emacs@m.gmane.org; Tue, 19 Apr 2005 21:10:20 -0400 Original-Path: shelby.stanford.edu!newsfeed.stanford.edu!postnews.google.com!f14g2000cwb.googlegroups.com!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 48 Original-NNTP-Posting-Host: 198.74.20.74 Original-X-Trace: posting.google.com 1113959086 13817 127.0.0.1 (20 Apr 2005 01:04:46 GMT) Original-X-Complaints-To: groups-abuse@google.com Original-NNTP-Posting-Date: Wed, 20 Apr 2005 01:04:46 +0000 (UTC) User-Agent: G2/0.2 Complaints-To: groups-abuse@google.com Injection-Info: f14g2000cwb.googlegroups.com; posting-host=198.74.20.74; posting-account=C7LM4w0AAAD23IRuMuUUJVCLQTuHhTK8 Original-Xref: shelby.stanford.edu gnu.emacs.help:130273 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:25841 X-Report-Spam: http://spam.gmane.org/gmane.emacs.help:25841 > > and use of functions such as fset and put have undefined results > > (which I showed in my examples). > > No, you didn't. You uninterned the symbol, after which it was no > longer available under the name 'foo. > > But if you had done (setq woozle 'foo) before uninterning it, > woozle would have continued to be a perfectly valid handle to the > symbol, even though 'foo no longer was able to access it. After all the coding I've done I had no idea my understanding of what was going on was so fundamentally flawed. It's easy to pinpoint just where this missunderstanding stems from though. Elisp reference: 8. Symbols A symbol is an object with a unique name. 8.3 Creating and Interning Symbols To understand how symbols are created in GNU Emacs Lisp, you must know how Lisp reads them. Lisp must ensure that it finds the same symbol every time it reads the same set of characters. Failure to do so would cause complete confusion. I was under the impression that let must be creating a symbol with the name I specified if one didn't already exist. Many tests seemed to confirm this view but some did not, triggering this dialog. What you appear to be saying is that 1. symbols do not have unique names they have unique handles. 2. the lisp reader won't necessarily find the same symbol every time. It will find whatever symbol is interned in the global obarray with a name equal to the name being read at the time. So, although it almost always is the same, nothing actually ensures it is the same. Hopefully there are no more such flaws in my understanding. I appreciate all the patience, and more importantly, persistance in getting me straightened out. Thanks