From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'? Date: Sat, 18 Feb 2023 14:00:19 +0200 Message-ID: <83bklryyi4.fsf@gnu.org> References: <87v8pw1xyo.fsf@localhost> <83a678d5w6.fsf@gnu.org> <878rmr25tk.fsf@localhost> <83czc3bvbg.fsf@gnu.org> <87y1urybt6.fsf@localhost> <837d2bbr2s.fsf@gnu.org> <87edwjy77h.fsf@localhost> <831qsjboy0.fsf@gnu.org> <87v8puw945.fsf@localhost> <838rmq9rfr.fsf@gnu.org> <837d2a9qcu.fsf@gnu.org> <875yhtw3ed.fsf@localhost> <831qmo146g.fsf@gnu.org> <83wn4fzcl5.fsf@gnu.org> <87y1ovjjei.fsf@localhost> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="19299"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 57693@debbugs.gnu.org, stefankangas@gmail.com, yantar92@gmail.com To: Ihor Radchenko Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat Feb 18 13:01:25 2023 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1pTLu9-0004tW-Ke for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 18 Feb 2023 13:01:25 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pTLtr-0007ns-PN; Sat, 18 Feb 2023 07:01:08 -0500 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 1pTLtm-0007nA-QG for bug-gnu-emacs@gnu.org; Sat, 18 Feb 2023 07:01:03 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pTLtm-0006lH-96 for bug-gnu-emacs@gnu.org; Sat, 18 Feb 2023 07:01:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1pTLtm-0001m4-3f for bug-gnu-emacs@gnu.org; Sat, 18 Feb 2023 07:01:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 18 Feb 2023 12:01:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 57693 X-GNU-PR-Package: emacs Original-Received: via spool by 57693-submit@debbugs.gnu.org id=B57693.16767216486795 (code B ref 57693); Sat, 18 Feb 2023 12:01:02 +0000 Original-Received: (at 57693) by debbugs.gnu.org; 18 Feb 2023 12:00:48 +0000 Original-Received: from localhost ([127.0.0.1]:42712 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pTLtY-0001lW-D2 for submit@debbugs.gnu.org; Sat, 18 Feb 2023 07:00:48 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:43234) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pTLtW-0001lK-39 for 57693@debbugs.gnu.org; Sat, 18 Feb 2023 07:00:46 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pTLtO-0006dp-IF; Sat, 18 Feb 2023 07:00:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=7WAUIFAO3Z5m2CuDu5RYSBeGQTfwpfaSTu4BRLFf9TU=; b=EhRxkXiYHS77 lOHjZoCB8uof2UhRN8wN/E05J1sqQ/NMPqt+XIKORNoinvYIEHNAx238LBQbz6OT7eYr28vbb+pR3 Zxn+GTRQVcV4Nt6+xsnHA295q08UayltMJt5WsyJWb50R+iUh+Tjw3bCs5ZzbT9QXh2RUyrBbd6pg +8VTQIpUc9MLE3sAaXBGqraYkEaLC1x+QFcEoTFDOJPt6PyWVDaF0mX1nV2scqERlq2Mpeux6KuA+ 4wYBplIJNND5lEcbvkAJSpKSUWkcCpGRh+5mi8ahlsoB4q0cuaNKq0ISkvhZHpyh+Dr8jsJIgP9/I NuSrr8qZYPVjia0N/gYsgQ==; Original-Received: from [87.69.77.57] (helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pTLt6-0003tx-S8; Sat, 18 Feb 2023 07:00:33 -0500 In-Reply-To: <87y1ovjjei.fsf@localhost> (message from Ihor Radchenko on Sat, 18 Feb 2023 11:35:33 +0000) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:255961 Archived-At: > From: Ihor Radchenko > Cc: Stefan Kangas , yantar92@gmail.com, > 57693@debbugs.gnu.org > Date: Sat, 18 Feb 2023 11:35:33 +0000 > > Eli Zaretskii writes: > > > If you need to care for TTY frames, that problem has no known solution > > that works for all terminal emulators. So using fancy characters in > > general-purpose Emacs features is a problem that cannot be solved > > programmatically, or at least we don't currently know how to do that. > > I am not sure if it is relevant, but I see > https://unix.stackexchange.com/questions/184345/detect-how-much-of-unicode-my-terminal-supports-even-through-screen > > May it be something of use for Emacs? If you are asking about the Linux console, then we already have a way of asking it whether it supports a given character. If you are asking about the kludges they suggest for other terminals, where we are supposed to deduce support fro a character by counting columns, then that is both unreliable and extremely cumbersome (we'd need to try to actually display a character in order to know whether its displayable).