From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stephen Berman Newsgroups: gmane.emacs.devel Subject: Re: What is a preferred charset? Date: Thu, 22 Nov 2018 10:07:00 +0100 Message-ID: <87muq1bhvv.fsf@gmx.net> References: <87zhu24h0b.fsf@gmx.net> <87r2fe4bru.fsf@gmx.net> <83o9aigj29.fsf@gnu.org> <87in0q3va0.fsf@gmx.net> <83lg5lhjby.fsf@gnu.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1542877572 14085 195.159.176.226 (22 Nov 2018 09:06:12 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 22 Nov 2018 09:06:12 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) Cc: schwab@suse.de, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Nov 22 10:06:08 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gPkw4-0003Wr-3q for ged-emacs-devel@m.gmane.org; Thu, 22 Nov 2018 10:06:08 +0100 Original-Received: from localhost ([::1]:44791 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gPkyA-0004qi-5I for ged-emacs-devel@m.gmane.org; Thu, 22 Nov 2018 04:08:18 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:42161) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gPkx5-0004pN-JF for emacs-devel@gnu.org; Thu, 22 Nov 2018 04:07:12 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gPkx0-0002ZF-JJ for emacs-devel@gnu.org; Thu, 22 Nov 2018 04:07:11 -0500 Original-Received: from mout.gmx.net ([212.227.17.22]:37155) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gPkx0-0002YD-2M; Thu, 22 Nov 2018 04:07:06 -0500 Original-Received: from rosalinde ([178.9.97.89]) by mail.gmx.com (mrgmx102 [212.227.17.168]) with ESMTPSA (Nemesis) id 0MNO33-1gNp0O2UuX-006zJF; Thu, 22 Nov 2018 10:07:01 +0100 In-Reply-To: <83lg5lhjby.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 22 Nov 2018 05:39:13 +0200") X-Provags-ID: V03:K1:vVX3S/iBmk4OKwN6zau4Y3APz1fiaRX4i2sJBVZU54DqC+1Xpio 853ZxhQZHdSPfFDAVPemzhGUyu0ViGv5tfpqn7j3pVIQwLxI7CBQPSzfULPDZOdGgfy8FLM PqhukLoFouzO+rKCGAe4fi1igtWXI9APK/EwttLjNdOpmjzcLkhUFhrM6hj+My7472mQOzG TzCN+CjFQVcQKSV3C2DbA== X-UI-Out-Filterresults: notjunk:1;V03:K0:ukycgrhbzjw=:Bo1XDyPHEMswz2T8hCIVeQ OZHMSehP5Hrb8igm3VEpknJ87NJzqnFeeuTXALG4zBII4z+7FKJ3AOr2bj8j3Yd4r/13mdpSN MHs2bIZqwkmfmsirq2OPP7U3odK/NlwPOr5K3mtlUPpSilNcr76THrkjOpjsOyFUJf3Uhn1TR 5I2LOOrrXafeEJWZuzxrNrd3zEL0c1Cj0C83f/IayOAbMvI+77PnrT+Ca+oPl/gxCDD3c4jRY LLoXxDUzlCuR7cS0V9nSzY2qdw3I5qQEwlvy0HQ01Eny2vGSe6owr/WZb3MxnZevatP/k/zDK vrmFfONOEh8x2K05GNIIgzCQGX/52m2HChbX5ovZ653SHEKmCCK0X6gjgUee/0tbgfk6CXLmD F2kTM121P21tJxKF1HU4Y3uWknH/fCPYyB7guZJ1iJXVcwJiZdXHRJWFd0LjDsuZlRPMlVXFQ 67FZ5IC9BT3eYa4bCjm/d+GCw1a0FoBiqIDdVWJ+vRFGEPyHNpfVMsDbasGIh+2bXFMMuG0i4 MjkUFOBz86/DU5ENq0EHLOZ3b6zk0ei/YPvzzGBOclKf1mvRNeO6su8bmeQg/9k8k6I0fxC/7 Ov+2UKDTyYEeMWreSzD8Nr5ciqo/m7ssj2BrBilAw+mS5OS5pEtzr2at850unLVyP9ADB+DhZ xxzVIfkPIxjSSi5sqY+MecDpnBV/VaDLAjqwvuTRKAn3GnoWomxqB/7iHt4d3Sr298lgaD/VY onVFdTyL5yz/9lDtECYPLhndJNRhT5x0io1ZGtz1KUeB832IN7zGBJpPHY1YKiSumVKUeEp3 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 212.227.17.22 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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" Xref: news.gmane.org gmane.emacs.devel:231303 Archived-At: On Thu, 22 Nov 2018 05:39:13 +0200 Eli Zaretskii wrote: >> From: Stephen Berman >> Cc: schwab@suse.de, emacs-devel@gnu.org >> Date: Wed, 21 Nov 2018 23:44:55 +0100 >> >> >> > In the case of HELLO, each hello phrase was given the 'charset' >> >> > property corresponding to its language's script, so as to instruct >> >> > Emacs to choose the most appropriate font for that greeting. >> >> >> >> ...this seems to be a different criterion for preferred, not the highest >> >> priority as defined above >> > >> > Not a different criterion, it's just that the 'charset' text property >> > overrides the charset priority order (as you'd expect). >> >> But why override the priority order if the preferred charset by that >> criterion (namely unicode, in this case) works (i.e. the character is >> correctly displayed)? I guess because there are cases where the >> preferred charset according to priority order fails? > > It is not a question of success or failure: every charset which > supports the character "succeeds". We choose one of them in order to > produce the effect (such as select a font for displaying it) that > suits best what this particular user in this particular case expects. > When text comes from an encoding that specifies its charset (such as > Latin-N), we can determine that charset from the encoding; if not, we > use the charset-priority order that is determined by the locale, as > fallback. So "preferred charset" means "charset the encoding specifies, if any, otherwise the locale-specific highest priority charset"? If so, it's still not clear to me why HELLO specifies charsets that (at least in some cases, like INVERTED EXCLAMATION MARK) differ from the highest priority; is it because the specified charsets are known to correctly display the characters regardless of locale (if that's even possible), while it's not known whether the highest priority charset can correctly display them? In any case, it's ok with me to drop this now, since it's become clear to me that "preferred charset" is not a technical term but a term of convenience used only by describe-char, and it hasn't bothered anyone till now (and I hadn't thought about it till now either). Thanks for the feedback. Steve Berman