From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Ulrich Mueller Newsgroups: gmane.emacs.devel Subject: Re: Case mapping of sharp s Date: Fri, 20 Nov 2009 15:43:05 +0100 Message-ID: <19206.43769.74889.573244@a1i15.kph.uni-mainz.de> References: <4B05A11F.5000700@gmx.de> <87iqd6gmpk.fsf@lola.goethe.zz> <19206.20213.843972.495981@a1i15.kph.uni-mainz.de> <876395e7vi.fsf@uwakimon.sk.tsukuba.ac.jp> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1258728277 19650 80.91.229.12 (20 Nov 2009 14:44:37 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 20 Nov 2009 14:44:37 +0000 (UTC) Cc: David Kastrup , emacs-devel@gnu.org To: "Stephen J. Turnbull" Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Nov 20 15:44:29 2009 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 4.50) id 1NBUim-0002AM-K3 for ged-emacs-devel@m.gmane.org; Fri, 20 Nov 2009 15:44:24 +0100 Original-Received: from localhost ([127.0.0.1]:40841 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NBUim-0004s3-3b for ged-emacs-devel@m.gmane.org; Fri, 20 Nov 2009 09:44:24 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NBUhj-0004QA-JE for emacs-devel@gnu.org; Fri, 20 Nov 2009 09:43:19 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NBUhe-0004OC-PR for emacs-devel@gnu.org; Fri, 20 Nov 2009 09:43:19 -0500 Original-Received: from [199.232.76.173] (port=54304 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NBUhe-0004O4-Hk for emacs-devel@gnu.org; Fri, 20 Nov 2009 09:43:14 -0500 Original-Received: from a1iwww1.kph.uni-mainz.de ([134.93.134.1]:48585) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NBUhb-0001Xb-AA; Fri, 20 Nov 2009 09:43:11 -0500 Original-Received: from a1i15.kph.uni-mainz.de (a1i15.kph.uni-mainz.de [134.93.134.92]) by a1iwww1.kph.uni-mainz.de (8.14.0/8.13.4) with ESMTP id nAKEh57Y010855; Fri, 20 Nov 2009 15:43:05 +0100 Original-Received: from a1i15.kph.uni-mainz.de (localhost [127.0.0.1]) by a1i15.kph.uni-mainz.de (8.14.3/8.14.2) with ESMTP id nAKEh5nl025698; Fri, 20 Nov 2009 15:43:05 +0100 Original-Received: (from ulm@localhost) by a1i15.kph.uni-mainz.de (8.14.3/8.14.3/Submit) id nAKEh5vv025695; Fri, 20 Nov 2009 15:43:05 +0100 In-Reply-To: <876395e7vi.fsf@uwakimon.sk.tsukuba.ac.jp> X-Mailer: VM 8.0.12 under 23.1.1 (x86_64-pc-linux-gnu) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 1) 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:117360 Archived-At: >>>>> On Fri, 20 Nov 2009, Stephen J Turnbull wrote: >> When the search is for equivalence classes of characters (e.g. case >> folding), then I think it must operate on whole characters and >> therefore has to find the start of each multibyte sequence. > This is false for certain equivalence classes, namely those that > cause only one octet of the multibyte representation to change. For > Mule encoding, this works for ranges of 96 characters, such as all > the unibyte charsets. For UTF-8, it works for ASCII, and IIRC for > letters in the Latin-1 set, and maybe many other Latin letters. And how do you know that a UTF-8 encoded character is e.g. in the Latin-1 set, without testing the first byte(s) of the multibyte sequence? Ulrich