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: Inconsistencies regarding nil coding-system Date: Mon, 13 Dec 2010 16:45:53 +0900 Message-ID: References: <83aakcvbtp.fsf@gnu.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1292226376 14756 80.91.229.12 (13 Dec 2010 07:46:16 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Mon, 13 Dec 2010 07:46:16 +0000 (UTC) Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Dec 13 08:46:12 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 1PS36o-0004Cu-Rs for ged-emacs-devel@m.gmane.org; Mon, 13 Dec 2010 08:46:11 +0100 Original-Received: from localhost ([127.0.0.1]:36814 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PS36o-0003Xr-4l for ged-emacs-devel@m.gmane.org; Mon, 13 Dec 2010 02:46:10 -0500 Original-Received: from [140.186.70.92] (port=41006 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PS36e-0003Uy-W1 for emacs-devel@gnu.org; Mon, 13 Dec 2010 02:46:02 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PS36d-0006Ew-P3 for emacs-devel@gnu.org; Mon, 13 Dec 2010 02:46:00 -0500 Original-Received: from mx1.aist.go.jp ([150.29.246.133]:55130) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PS36b-0006Dy-RT; Mon, 13 Dec 2010 02:45:58 -0500 Original-Received: from rqsmtp2.aist.go.jp (rqsmtp2.aist.go.jp [150.29.254.123]) by mx1.aist.go.jp with ESMTP id oBD7jsCC005513; Mon, 13 Dec 2010 16:45:54 +0900 (JST) env-from (handa@m17n.org) Original-Received: from smtp4.aist.go.jp by rqsmtp2.aist.go.jp with ESMTP id oBD7jsfs023149; Mon, 13 Dec 2010 16:45:54 +0900 (JST) env-from (handa@m17n.org) Original-Received: by smtp4.aist.go.jp with ESMTP id oBD7jrQt010743; Mon, 13 Dec 2010 16:45:53 +0900 (JST) env-from (handa@m17n.org) Original-Received: from handa by etlken with local (Exim 4.71) (envelope-from ) id 1PS36X-0001f9-IP; Mon, 13 Dec 2010 16:45:53 +0900 In-Reply-To: <83aakcvbtp.fsf@gnu.org> (message from Eli Zaretskii on Sat, 11 Dec 2010 12:33:06 +0200) X-detected-operating-system: by eggs.gnu.org: Solaris 9 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:133640 Archived-At: In article <83aakcvbtp.fsf@gnu.org>, Eli Zaretskii writes: > (coding-system-change-eol-conversion nil 'unix) => nil > (coding-system-change-text-conversion 'latin-1-dos nil) => undecided-dos > (coding-system-base nil) => no-conversion > When primitives that encode/decode text accept nil as their > coding-system argument, they use `undecided' (AFAIK). So the second > result above looks reasonable, but the first and the last are > inconsistent, and the last one is downright surprising. > Any reasons not to change coding-system-change-eol-conversion and > coding-system-base to consistently treat nil as `undecided'? (If > agreed to, I suggest to make this change only on the trunk, not on the > release branch.) When I first introduced coding-system, nil was for no-conversion, and t was for undecided, and as time passed, we have shifted to `no-conversion' and `undecided'. But, some old codes still treat nil for `no-conversion' and new codes consider nil as "unspecified" and thus treat it as `undecided'. Perhaps, ver. 24 is a good timing to wipe out this confusion, but I'm not sure how to treat nil. Nil should usually mean "unspecified", and what exactly "unspecified" means depends on a situaion. --- Kenichi Handa handa@m17n.org