From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: MON KEY Newsgroups: gmane.emacs.devel Subject: Re: `setplist' on local var escaping let binding Date: Wed, 20 Oct 2010 23:02:07 -0400 Message-ID: References: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: dough.gmane.org 1287630155 7102 80.91.229.12 (21 Oct 2010 03:02:35 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 21 Oct 2010 03:02:35 +0000 (UTC) Cc: emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Oct 21 05:02:34 2010 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 4.69) (envelope-from ) id 1P8lQ4-0000bI-Br for ged-emacs-devel@m.gmane.org; Thu, 21 Oct 2010 05:02:31 +0200 Original-Received: from localhost ([127.0.0.1]:37025 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1P8lQ2-0005ac-1x for ged-emacs-devel@m.gmane.org; Wed, 20 Oct 2010 23:02:18 -0400 Original-Received: from [140.186.70.92] (port=48490 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1P8lPu-0005aM-RV for emacs-devel@gnu.org; Wed, 20 Oct 2010 23:02:11 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1P8lPt-0007ce-Hz for emacs-devel@gnu.org; Wed, 20 Oct 2010 23:02:10 -0400 Original-Received: from mail-wy0-f169.google.com ([74.125.82.169]:36846) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1P8lPt-0007ca-Ce for emacs-devel@gnu.org; Wed, 20 Oct 2010 23:02:09 -0400 Original-Received: by wyf28 with SMTP id 28so4739565wyf.0 for ; Wed, 20 Oct 2010 20:02:08 -0700 (PDT) Original-Received: by 10.216.50.134 with SMTP id z6mr359194web.15.1287630127948; Wed, 20 Oct 2010 20:02:07 -0700 (PDT) Original-Received: by 10.216.67.195 with HTTP; Wed, 20 Oct 2010 20:02:07 -0700 (PDT) In-Reply-To: X-Google-Sender-Auth: k6NTT5sfn_RmbktxQ9JnGJkr6HA X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) 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:131923 Archived-At: On Wed, Oct 20, 2010 at 9:10 PM, Stefan Monnier wrote: >> I noticed today that if I `setplist' on a null let bound local var > > The above shows a misunderstanding: setplist does not operate on > variables but on symbols. What is this then: 'a-quoted-variable-but-not-a-symbol ? Are you saying that `setplist' is only for top-level symbols? Doesn't quoting the variable intern? (let (ms) (setplist 'ms '(can-has a-plist)) `(,(get 'ms 'can-has) ,(intern-soft "ms" obarray))) ;=> (a-plist ms) (get 'ms 'can-has) ;=> a-plist Appears to. Whichever. I still don't understand how/why following happens (nor how your answer addresses it): (progn (unintern "ms" obarray) (let (ms) (setplist 'ms '(can-has a-plist)) `(,(get 'ms 'can-has) ,(intern-soft "ms" obarray)))) (a-plist nil) ;=> (a-plist nil) (get 'ms 'can-has) ;=> nil So what am i missing? In following `ms' is a "thing-like" bound to an uninterned "non-thing" `bubba'. `ms' is on obarray `bubba' isn't and his symbol-value void. (let ((ms (make-symbol "bubba"))) (list :thing-like (intern-soft "ms" obarray) :non-thing (intern-soft "bubba" obarray))) ;=> (:thing-like ms :non-thing nil) make sure its all clear: (progn (intern-soft "bubba" obarray) (unintern "bubba" obarray) (intern-soft "ms" obarray) (unintern "ms" obarray)) In following the "non-thing" `bubba' has a plist and the thing-like is interned: (let ((ms (make-symbol "bubba"))) (apply #'setplist (list (eval (list 'quote (identity ms))) '(not a symbol really?))) `(:non-thing-bubba ,(not (intern-soft "bubba" obarray)) :but-with-a-plist ,(apply #'get (list (eval (list 'quote (identity ms))) 'symbol)) :is-thing-like-ms ,(eq (intern-soft "ms" obarray) (intern-soft "ms" obarray)))) ;=> (:non-thing-bubba t ; :but-with-a-plist really\? ; :is-thing-like-ms t) > Stefan -- /s_P\