From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Dave Love Newsgroups: gmane.emacs.devel Subject: Re: display table for eight-bit-graphic Date: 03 Feb 2003 14:32:44 +0000 Sender: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Message-ID: References: <200301250116.KAA11729@etlken.m17n.org> <200301270220.LAA14193@etlken.m17n.org> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: main.gmane.org 1044282719 4452 80.91.224.249 (3 Feb 2003 14:31:59 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Mon, 3 Feb 2003 14:31:59 +0000 (UTC) Cc: emacs-devel@gnu.org Return-path: Original-Received: from quimby.gnus.org ([80.91.224.244]) by main.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 18fhdd-00019R-00 for ; Mon, 03 Feb 2003 15:31:57 +0100 Original-Received: from monty-python.gnu.org ([199.232.76.173]) by quimby.gnus.org with esmtp (Exim 3.12 #1 (Debian)) id 18fhlG-0008LQ-00 for ; Mon, 03 Feb 2003 15:39:50 +0100 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 18fhep-0001cB-09 for emacs-devel@quimby.gnus.org; Mon, 03 Feb 2003 09:33:11 -0500 Original-Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.10.13) id 18fheW-0001WW-00 for emacs-devel@gnu.org; Mon, 03 Feb 2003 09:32:52 -0500 Original-Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.10.13) id 18fheU-0001UB-00 for emacs-devel@gnu.org; Mon, 03 Feb 2003 09:32:51 -0500 Original-Received: from albion.dl.ac.uk ([148.79.80.39]) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 18fheS-0001Sk-00; Mon, 03 Feb 2003 09:32:49 -0500 Original-Received: from fx by albion.dl.ac.uk with local (Exim 3.36 #1 (Debian)) id 18fheO-0008OI-00; Mon, 03 Feb 2003 14:32:45 +0000 Original-To: Kenichi Handa Original-Lines: 57 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 Original-cc: rms@gnu.org X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1b5 Precedence: list List-Id: Emacs development discussions. List-Help: List-Post: List-Subscribe: , List-Archive: List-Unsubscribe: , Errors-To: emacs-devel-bounces+emacs-devel=quimby.gnus.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:11315 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:11315 Kenichi Handa writes: > What I object is to setting up the display table as now by default. Likewise. [The original of these never reached me:] > kai.grossjohann@uni-duisburg.de (Kai Gro=DFjohann) writes: > > "Ehud Karni" writes: >=20 > >> I agree. For persons in the ISO-8859-x languages, the 8 bit graphics > >> is much better than the octal representation. Displaying them as graphics is actually worse for people in locales where the graphics might make sense, but are actually misleading. Do you really want undecodeable utf-8 byte sequences, or GBK &c, to display as Hebrew characters? > > It might seem so at first sight, but there are problems later on: for > > instance, you can't search for the 8bit graphics characters by typing > > Latin-1 characters, and people will surely be *very* surprised that > > they can't find their characters! The point is that these aren't actually well-defined characters -- they're random bytes. If you were sure they represented, say, Latin-1 code points, you could treat them similarly to equivalent characters from other charsets using translation-table-for-input, but then you should have decoded the text correctly. > I agree with that. Showing different characters by the same > glyph is the source of confusion at least for novice users. That sort of thing is also a possible security-type risk. There are potential exploits from conning people into thinking the text is different from what it actually is. > > Maybe it would be useful to highlight the graphics characters in some > > way so that it is clear that they aren't normal characters. >=20 > I'm not sure that is a good idea. Highlighting means many > things. Octal displaying is far better to indicate that > they aren't normal characters. Exactly. The only reasonable alternative would be to display them with single-width glyphs or suitably-propertized text that displayed the binary values somehow. I think Yudit does that, but I wouldn't suggest following it, especially as the glyph contents would typically be too small. [It is, in principle, a good idea to flag possibly confusing characters with faces, such as latin1-disp now allows. That doesn't actually work well in practice, since the face information allowed in the display table doesn't get merged by redisplay. Thus if you underline substitutions, they don't inherit the foreground/background of the adjacent text. I don't know whether or not this is actually a bug.]