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.devel Subject: so-long-mode and line-move-visual Date: Sun, 08 May 2022 08:44:58 +0300 Message-ID: <83sfpkwpb9.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="20799"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Phil Sainty Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun May 08 07:46:56 2022 Return-path: Envelope-to: ged-emacs-devel@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 1nnZku-0005II-4V for ged-emacs-devel@m.gmane-mx.org; Sun, 08 May 2022 07:46:56 +0200 Original-Received: from localhost ([::1]:44014 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nnZks-0000Qm-HM for ged-emacs-devel@m.gmane-mx.org; Sun, 08 May 2022 01:46:54 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34210) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nnZjD-0007yz-ID for emacs-devel@gnu.org; Sun, 08 May 2022 01:45:11 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:50232) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nnZjC-0002AS-1p; Sun, 08 May 2022 01:45:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=Subject:To:From:Date:mime-version:in-reply-to: references; bh=mwmLPC+ld1Ml5bOeHyjj9kMV/Lpo5EtEvrf3tPR8FYM=; b=rVi4OFoN8DM7Gq 9usSA9Xw/5R8TFiELcLEH+NNBJHivbOBctgsKWEa9m4CVH+Tjz5ZUTUDVH1b546Y2FHnnPTxtPzsg 14aAqPiaAxbTMyJPz61dlI7S9btQY9YVVKOsZYnPaoJmQaoWbQ9WlFEskYp6LFExd849BLr8t0v9C LMvQ4TMmLiZcH9oinsoyklWZuyBKYj+y/27a/U3vZQxU2fOHfW4cAe1k4ddI2czHLCJNLC/SPOtl8 HOENRO4XpHWb5bf65fSoOj90aUE6ZLgZbpriJNj8EHT78mraE2I2kbObCwlWu5knbq1I/qjlTbCxA ZxeWeujhBKpFFaYZTnyA==; Original-Received: from [87.69.77.57] (port=4750 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 1nnZj7-0001Y6-HD; Sun, 08 May 2022 01:45:09 -0400 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:289443 Archived-At: Phil, so-long.el has this passage: (defcustom so-long-variable-overrides '((bidi-inhibit-bpa . t) (bidi-paragraph-direction . left-to-right) (buffer-read-only . t) (global-hl-line-mode . nil) (line-move-visual . t) (show-paren-mode . nil) (truncate-lines . nil) (which-func-mode . nil)) "Variables to override, and the values to override them with. The variables are given buffer-local values. By default this happens if `so-long-action' is set to either `so-long-mode' or `so-long-minor-mode'. If `so-long-revert' is subsequently invoked, then the variables are restored to their original states. The combination of `line-move-visual' (enabled) and `truncate-lines' (disabled) is important for maximising responsiveness when moving vertically within an extremely long line, as otherwise the full length of the line may need to be scanned to find the next position. It looks to me that the last paragraph (and the overrides to go with it) has it backwards: line-move-visual set to nil produces _better_ performance than a non-nil value, and if truncate-lines is turned on, the boost is even larger. the explanation why is that so is correct, but it describes the situation that's the opposite of the settings we recommend. I wonder why and how we came to the conclusion recorded in the current code and the doc string. Or what am I missing?