From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings Newsgroups: gmane.emacs.devel Subject: Re: Suggested experimental test Date: Tue, 23 Mar 2021 21:06:54 +0000 Message-ID: <22aaf0fadda0f9d9bc03@heytings.org> References: <831ba60af0cbfdd95686@heytings.org> <87mtuxj8ue.fsf@gnus.org> <9088e12cb3de3d30abf1@heytings.org> <8735wnjsum.fsf@gnus.org> <83sg4n9jei.fsf@gnu.org> <271290d7aac58f2f9e96@heytings.org> <83czvr9hvc.fsf@gnu.org> <271290d7aa69bbcaa204@heytings.org> <83lfae8fbg.fsf@gnu.org> <22aaf0fadd0894af49d9@heytings.org> <83v99i6ink.fsf@gnu.org> <22aaf0fadd0870c0e9f8@heytings.org> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="32855"; mail-complaints-to="usenet@ciao.gmane.io" Cc: eliz@gnu.org, larsi@gnus.org, emacs-devel@gnu.org To: "Alfred M. Szmidt" Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Mar 23 22:08:23 2021 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 1lOoGF-0008RS-HF for ged-emacs-devel@m.gmane-mx.org; Tue, 23 Mar 2021 22:08:23 +0100 Original-Received: from localhost ([::1]:57092 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lOoGE-0002Le-HZ for ged-emacs-devel@m.gmane-mx.org; Tue, 23 Mar 2021 17:08:22 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:35880) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lOoEt-0000sh-Co for emacs-devel@gnu.org; Tue, 23 Mar 2021 17:06:59 -0400 Original-Received: from heytings.org ([95.142.160.155]:42586) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lOoEr-0005xN-L5; Tue, 23 Mar 2021 17:06:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heytings.org; s=20210101; t=1616533615; bh=XDAzgKlPv0I+3NysNGYasp4cL3XotAzhky7aPIMkOg8=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:From; b=U5cwGFqtUeCjnWeedcv4wncKf5Z4v1QteXYQGOZqg5AUS0cmJtsHc2dbzWLsmvktn tKoe7k63IWp23TDDHcfT8WSVrUHyPoHixyyIJo6JiBLxr6+/ME2XhMitpHlPF1exUk Lp0ZUGzfgEOdXSPPV/swBI/iU1CFEizsYRYhUvUShcvgCM/6lYQvyfb1yb3FRLLnXh +jl0dnXeGEhKrqLxt92So3rYdZz7KU3m0BgBH5Bg4DR8/lpfTdHA22wQ3QHwvPtqDH JOHZadhflpW6kTIS6fjDcYza2KGJev8mRGQzIrshRTCxucu71K7TDXuv6zWVRbl1dc gkCmpzTd5zs/g== In-Reply-To: Received-SPF: pass client-ip=95.142.160.155; envelope-from=gregory@heytings.org; helo=heytings.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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:266893 Archived-At: > > C-o is bound where it is because when Emacs was written, someone -- most > probpobly RMS -- bound it there, so it isn't really a historical > accident but rather an active design decision. There is also a reason > why C-x C-o where it is. > I digged further in my archives. In case some are interested: As most of you know, the original Emacs was written in TECO. C-o was a command of TECO's real-time editing feature (which was entered with C-r), which was imported into Emacs. The purpose of C-o in TECO was to optimize redisplay: when point on in the middle of a non-empty line, C-o F O O required less redisplay than F O O RET. C-o in the original Emacs didn't quite do what C-o now does: the line(s) created by C-o were "eated" by the text that was inserted. In other words, RET in the line(s) created with C-o did not push the next lines down, it went on the next created line (if any). In other words again, let's assume the following initial situation: A |D E where | is the point. After C-u 2 C-o B RET C RET, the buffer was now: A B C |D E In other words again, C-o was meant to "create some blank space on the screen" (not in the buffer) to optimize redisplay. Do you now see the "historical accident"?