From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: ludo@gnu.org (Ludovic =?iso-8859-1?Q?Court=E8s?=) Newsgroups: gmane.lisp.guile.user Subject: Re: Dynamic variable binding Date: Fri, 19 Dec 2008 14:03:49 +0100 Message-ID: <877i5w71vu.fsf@gnu.org> References: <8wro202o.fsf@vps203.linuxvps.org> <200811130051.mAD0pReg006490@fcs13.keithdiane.us> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1229691926 7279 80.91.229.12 (19 Dec 2008 13:05:26 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 19 Dec 2008 13:05:26 +0000 (UTC) To: guile-user@gnu.org Original-X-From: guile-user-bounces+guile-user=m.gmane.org@gnu.org Fri Dec 19 14:06:32 2008 Return-path: Envelope-to: guile-user@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1LDf3V-00077H-GE for guile-user@m.gmane.org; Fri, 19 Dec 2008 14:06:13 +0100 Original-Received: from localhost ([127.0.0.1]:44516 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LDf2J-0002nb-8T for guile-user@m.gmane.org; Fri, 19 Dec 2008 08:04:59 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LDf1O-0002MK-Kz for guile-user@gnu.org; Fri, 19 Dec 2008 08:04:02 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LDf1M-0002Lt-UY for guile-user@gnu.org; Fri, 19 Dec 2008 08:04:02 -0500 Original-Received: from [199.232.76.173] (port=51221 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LDf1M-0002Ln-QZ for guile-user@gnu.org; Fri, 19 Dec 2008 08:04:00 -0500 Original-Received: from main.gmane.org ([80.91.229.2]:55315 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 1LDf1M-0005lQ-AD for guile-user@gnu.org; Fri, 19 Dec 2008 08:04:00 -0500 Original-Received: from list by ciao.gmane.org with local (Exim 4.43) id 1LDf1I-00065s-Oc for guile-user@gnu.org; Fri, 19 Dec 2008 13:03:56 +0000 Original-Received: from 193.50.110.227 ([193.50.110.227]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 19 Dec 2008 13:03:56 +0000 Original-Received: from ludo by 193.50.110.227 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 19 Dec 2008 13:03:56 +0000 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 20 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 193.50.110.227 X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 29 Frimaire an 217 de la =?iso-8859-1?Q?R=E9volution?= X-PGP-Key-ID: 0xEA52ECF4 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 821D 815D 902A 7EAB 5CEE D120 7FBA 3D4F EB1F 5364 X-OS: i686-pc-linux-gnu User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.3 (gnu/linux) Cancel-Lock: sha1:AetEtke6/yrz5XEpZ7SDclB7FHs= X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-BeenThere: guile-user@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: General Guile related discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: guile-user-bounces+guile-user=m.gmane.org@gnu.org Errors-To: guile-user-bounces+guile-user=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.user:7024 Archived-At: Hi, Sebastian Tennant writes: > My semantic point is that the first argument to definer (above) is not a > symbol and it's not a variable (an unbound variable error would be > thrown if it was), so in the context of the first agument to define > there is a third data type; 'variable name'. Beware: the term "variable" can refer to an object as returned by `make-variable', `module-variable', etc., in Guile parlance (info "(guile) Variables"). What happens with your `definer' macro is that the first argument of the macro is a symbol (that is, during the *macro expansion* phase). The result of `definer' (an sexp) is then itself evaluated, so that symbol becomes a reference to a variable (during the evaluation phase). Thanks, Ludo'.