From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Kenichi Handa Newsgroups: gmane.emacs.devel Subject: Re: safe_call1 considered harmful Date: Sun, 30 Jul 2006 18:18:48 +0900 Message-ID: References: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 (generated by SEMI 1.14.3 - "Ushinoya") Content-Type: text/plain; charset=US-ASCII X-Trace: sea.gmane.org 1154251200 10418 80.91.229.2 (30 Jul 2006 09:20:00 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Sun, 30 Jul 2006 09:20:00 +0000 (UTC) Cc: eliz@gnu.org, emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Jul 30 11:19:57 2006 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1G77Sm-0000kU-R5 for ged-emacs-devel@m.gmane.org; Sun, 30 Jul 2006 11:19:57 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1G77Sm-00012S-5x for ged-emacs-devel@m.gmane.org; Sun, 30 Jul 2006 05:19:56 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1G77Sa-0000zC-Oz for emacs-devel@gnu.org; Sun, 30 Jul 2006 05:19:44 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1G77SX-0000sx-L0 for emacs-devel@gnu.org; Sun, 30 Jul 2006 05:19:44 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1G77SX-0000sc-Db for emacs-devel@gnu.org; Sun, 30 Jul 2006 05:19:41 -0400 Original-Received: from [150.29.246.133] (helo=mx1.aist.go.jp) by monty-python.gnu.org with esmtp (Exim 4.52) id 1G77Ut-0007b7-S7; Sun, 30 Jul 2006 05:22:08 -0400 Original-Received: from smtp1.aist.go.jp ([150.29.246.12]) by mx1.aist.go.jp with ESMTP id k6U9JYC1020390; Sun, 30 Jul 2006 18:19:34 +0900 (JST) env-from (handa@m17n.org) Original-Received: by smtp1.aist.go.jp with ESMTP id k6U9JY8R028134; Sun, 30 Jul 2006 18:19:34 +0900 (JST) env-from (handa@m17n.org) Original-Received: from handa by etlken with local (Exim 3.36 #1 (Debian)) id 1G77Rg-0000dD-00; Sun, 30 Jul 2006 18:18:48 +0900 Original-To: rms@gnu.org In-reply-to: (message from Richard Stallman on Mon, 24 Jul 2006 14:22:04 -0400) User-Agent: SEMI/1.14.3 (Ushinoya) FLIM/1.14.2 (Yagi-Nishiguchi) APEL/10.2 Emacs/22.0.50 (i686-pc-linux-gnu) MULE/5.0 (SAKAKI) 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:57803 Archived-At: In article , Richard Stallman writes: > find-operation-coding-system calls a registered function > with a single argument; a list of arguments given to > find-operation-coding-system. So, appending an extra > argument at the tail of the list is fairly safe. > It might seem that way; but what happens if we change the calling > convention of one of the operations, giving it an additional argument? > That may be necessary some day. I prefer the current convention. We can change tar-mode/arc-mode/jka-compr to call find-operation-coding-system with full number of arguments plus the extra argument BUFFER. Then, a function called from find-operation-coding-system can check if the number of arguments is greater than the normal number (which can be checked by subr-arity). If it is greater, the function can know that the last argument is BUFFER. By that way, the function doesn't break even if we add a new argument to find-operation-coding-system. --- Kenichi Handa handa@m17n.org