From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Lisp object that refers to a C struct Date: Tue, 16 Oct 2012 05:53:52 +0200 Message-ID: <83bog33wdr.fsf@gnu.org> References: <83ehkz4edw.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1350359654 30070 80.91.229.3 (16 Oct 2012 03:54:14 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 16 Oct 2012 03:54:14 +0000 (UTC) Cc: emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Oct 16 05:54:22 2012 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1TNyEX-0008Vm-Dr for ged-emacs-devel@m.gmane.org; Tue, 16 Oct 2012 05:54:21 +0200 Original-Received: from localhost ([::1]:44085 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TNyEQ-0003Ra-H8 for ged-emacs-devel@m.gmane.org; Mon, 15 Oct 2012 23:54:14 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:35020) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TNyEO-0003RS-MP for emacs-devel@gnu.org; Mon, 15 Oct 2012 23:54:13 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TNyEN-0000zD-NG for emacs-devel@gnu.org; Mon, 15 Oct 2012 23:54:12 -0400 Original-Received: from mtaout20.012.net.il ([80.179.55.166]:58607) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TNyEN-0000yn-F7 for emacs-devel@gnu.org; Mon, 15 Oct 2012 23:54:11 -0400 Original-Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0MBY00800W0WEY00@a-mtaout20.012.net.il> for emacs-devel@gnu.org; Tue, 16 Oct 2012 05:53:42 +0200 (IST) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MBY007FVW5HLNB0@a-mtaout20.012.net.il>; Tue, 16 Oct 2012 05:53:42 +0200 (IST) In-reply-to: X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-Received-From: 80.179.55.166 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:154366 Archived-At: > From: Stefan Monnier > Cc: emacs-devel@gnu.org > Date: Mon, 15 Oct 2012 21:07:21 -0400 > > > There's Lisp_Save_Value, which looks very promising, > > Lisp_Save_Value is a Lisp_Misc. > > > but why does its documentation say it's for record_unwind_protect? > > Is there anything in it which would preclude its use > > outside unwinding? > > It doesn't look very pretty when printed, so it's generally better not > to expose it to users too much. If your value will usually not be > visible to Elisp code, then Lisp_Save_Value is perfectly fine. OK. > Otherwise, better define your own type so that its printed > representation can be more helpful, indicating what it's used for How do I define my own type? In particular, what to do with gcmarkbit in Lisp_Misc? > (I presume it's for a file-watch-descriptor). Yes.