From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ulrich Mueller Newsgroups: gmane.emacs.devel Subject: Re: Coding systems vietnamese-vscii and vietnamese-tcvn Date: Fri, 28 Jul 2023 20:03:10 +0200 Message-ID: References: <83zg3pzbm6.fsf@gnu.org> <83jzutbeim.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="23750"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Jul 28 20:50:04 2023 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qPSXM-0005wU-P5 for ged-emacs-devel@m.gmane-mx.org; Fri, 28 Jul 2023 20:50:04 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qPRo8-0005kX-Vu; Fri, 28 Jul 2023 14:03:21 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qPRo7-0005kP-N8 for emacs-devel@gnu.org; Fri, 28 Jul 2023 14:03:19 -0400 Original-Received: from woodpecker.gentoo.org ([140.211.166.183] helo=smtp.gentoo.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_CHACHA20_POLY1305:256) (Exim 4.90_1) (envelope-from ) id 1qPRo6-00030l-1a; Fri, 28 Jul 2023 14:03:19 -0400 In-Reply-To: <83jzutbeim.fsf@gnu.org> (Eli Zaretskii's message of "Fri, 21 Jul 2023 16:06:09 +0300") Received-SPF: pass client-ip=140.211.166.183; envelope-from=ulm@gentoo.org; helo=smtp.gentoo.org X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:308192 Archived-At: >>>>> On Fri, 21 Jul 2023, Eli Zaretskii wrote: >> From: Ulrich Mueller >> Cc: emacs-devel@gnu.org >> Date: Fri, 21 Jul 2023 14:52:55 +0200 >> >> >>>>> On Fri, 21 Jul 2023, Eli Zaretskii wrote: >> >> > Why is the fact that we have two separate coding systems a problem in >> > this case? >> >> Presumably it works fine as-is, but is there any benefit of having such >> duplication? > I cannot see any clear benefits either way. > Maybe we need to ask Vietnamese users. The comments in > lisp/language/vietnamese.el say that vscii is deprecated. I have asked a Vietnamese speaker. Paraphrasing their answer: VSCII is the encoding described in standard TCVN 5712:1993. The terms can be used interchangeably; there is no reason to have separate character tables. So the statement in the Vietnamese language info that "VSCII is deprecated in favor of TCVN-5712" doesn't appear to be correct; the two terms are synonyms for the same encoding. I also looked up the original standard. TCVN 5712:1993 defines two encodings which it names VN1 (aka VSCII-1) and VN2 (aka VSCII-2). VSCII-2 (VN2) defines these code points: - 0x00 to 0x7f are identical to ASCII, - 0x80 to 0x9f are the C1 controls, - 0xa0 to 0xff contain 96 non-ASCII characters. VSCII-1 (VN1) is different from VSCII-2 in that it also replaces code points 0x01-0x02, 0x04-0x06, 0x11-0x17, and 0x80-0x9f by 44 additional non-ASCII characters, for a total of 140 non-ASCII characters. There is also an updated standard TCVN 5712:1999 which mentions only one encoding identical to VSCII-1, i.e. VSCII-2 is no longer part of this later version of the standard. So I suggest to define only coding system vietnamese-vscii, and make vietnamese-tcvn an alias of it. If this a acceptable, I can prepare a patch for lisp/language/vietnamese.el.