From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Emacs 23 character code space Date: Sat, 22 Nov 2008 20:25:52 +0200 Message-ID: References: Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org X-Trace: ger.gmane.org 1227378393 31295 80.91.229.12 (22 Nov 2008 18:26:33 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 22 Nov 2008 18:26:33 +0000 (UTC) Cc: emacs-devel@gnu.org To: Kenichi Handa Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Nov 22 19:27:37 2008 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 1L3xCi-0007im-80 for ged-emacs-devel@m.gmane.org; Sat, 22 Nov 2008 19:27:36 +0100 Original-Received: from localhost ([127.0.0.1]:58705 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1L3xBY-0003hA-Uq for ged-emacs-devel@m.gmane.org; Sat, 22 Nov 2008 13:26:24 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1L3xBT-0003co-GV for emacs-devel@gnu.org; Sat, 22 Nov 2008 13:26:19 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1L3xBS-0003br-Sy for emacs-devel@gnu.org; Sat, 22 Nov 2008 13:26:19 -0500 Original-Received: from [199.232.76.173] (port=43203 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1L3xBS-0003bX-KV for emacs-devel@gnu.org; Sat, 22 Nov 2008 13:26:18 -0500 Original-Received: from mtaout5.012.net.il ([84.95.2.13]:62920) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1L3xBS-0005W6-F0 for emacs-devel@gnu.org; Sat, 22 Nov 2008 13:26:18 -0500 Original-Received: from conversion-daemon.i_mtaout5.012.net.il by i_mtaout5.012.net.il (HyperSendmail v2004.12) id <0KAQ00F00YSQYT00@i_mtaout5.012.net.il> for emacs-devel@gnu.org; Sat, 22 Nov 2008 20:27:51 +0200 (IST) Original-Received: from HOME-C4E4A596F7 ([77.126.14.29]) by i_mtaout5.012.net.il (HyperSendmail v2004.12) with ESMTPA id <0KAQ00EW4ZAF7E90@i_mtaout5.012.net.il>; Sat, 22 Nov 2008 20:27:51 +0200 (IST) In-reply-to: X-012-Sender: halo1@inter.net.il X-detected-operating-system: by monty-python.gnu.org: Solaris 9.1 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:105966 Archived-At: > From: Kenichi Handa > CC: emacs-devel@gnu.org > Date: Wed, 05 Nov 2008 21:27:54 +0900 > > Attached is the remaining part. Please reflect that to the > document. Thanks. I have a few questions about this: A character set is a set of characters, and it assigns a unique code point to each character belonging to the set. Emacs decodes a specific code point of a specific character set to an Emacs character. Does this mean a character set is equivalent to a coding-system, meaning that a coding-system is a mapping between a character set and the Emacs internal codepoints? @defun charset-dimension charset This function returns the dimension of @var{charset}. Here, dimension means the number of bytes required to represent the highest code point (not an Emacs character code) of a character. For example, the dimension of @code{iso-8859-1} is one, the dimension of @code{japanese-jisx0208} is two, and the dimension of @code{unicode} is three. @end defun I decided not to document this. I think the concept of charset dimension is too obscure to explain, and not really needed for Lisp programs, unless they need to define a new charset, or display a charset, and those are already done by Emacs infrastructure. Do you see any problems with not documenting this function? A translation table has two extra slots. The first is either @code{nil} or a translation table that performs the reverse translation; the second is the maximum number of characters to look up for translation. Could you please elaborate on the second extra slot: when and for what purpose would there be a need to look up characters for translation? TIA