From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: "Eric S. Raymond" Newsgroups: gmane.emacs.devel Subject: Re: Shrinking the C core Date: Wed, 9 Aug 2023 21:19:11 -0400 Organization: Eric Conspiracy Secret Labs Message-ID: References: <20230809094655.793FC18A4654@snark.thyrsus.com> <87il9owg0f.fsf@yahoo.com> Reply-To: esr@thyrsus.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="7995"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Po Lu Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Aug 10 03:20:14 2023 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 1qTuLV-0001uN-Tl for ged-emacs-devel@m.gmane-mx.org; Thu, 10 Aug 2023 03:20:13 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qTuKb-0001pP-Sd; Wed, 09 Aug 2023 21:19:17 -0400 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 1qTuKZ-0001pA-0A for emacs-devel@gnu.org; Wed, 09 Aug 2023 21:19:16 -0400 Original-Received: from thyrsus.com ([71.162.243.5] helo=snark.thyrsus.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qTuKX-00079H-53 for emacs-devel@gnu.org; Wed, 09 Aug 2023 21:19:14 -0400 Original-Received: by snark.thyrsus.com (Postfix, from userid 1000) id 4250318A4654; Wed, 9 Aug 2023 21:19:11 -0400 (EDT) Content-Disposition: inline In-Reply-To: X-Eric-Conspiracy: There is no conspiracy Received-SPF: pass client-ip=71.162.243.5; envelope-from=esr@thyrsus.com; helo=snark.thyrsus.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, 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: 2.1.29 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-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:308497 Archived-At: Po Lu : > "Eric S. Raymond" writes: > > > When I first worked on Emacs code in the 1980s Lisp was already fast > > enough, and machine speeds have gone up by something like 10^3 since. > > I plain don't believe the "slower" part can be an issue on modern > > hardware, not even on tiny SBCs. > > Can you promise the same, if your changes are not restricted to one or > two functions in fileio.c, but instead pervade throughout C source? Yes, in fact, I can. Because if by some miracle we were able to instantly rewrite the entirety of Emacs in Python (which I'm not advocating, I chose it because it's the slowest of the major modern scripting languages) basic considerations of clocks per second would predict it to run a *dead minimum* of two orders of magnitude faster than the Emacs of, say, 1990. And 1990 Emacs was already way fast enough for the human eye and brain, which can't even register interface lag of less than 0.17 seconds (look up the story of Jef Raskin and how he exploited this psychophysical fact in the design of the Canon Cat sometime; it's very instructive). The human auditory system can perceive finer timeslices, down to about 0.02s in skilled musicians, but we're not using elisp for audio signal processing. If you take away nothing else from this conversation, at least get it through your head that "more Lisp might make Emacs too slow" is a deeply, *deeply* silly idea. It's 2023 and the only ways you can make a user-facing program slow enough for response lag to be noticeable are disk latency on spinning rust, network round-trips, or operations with a superlinear big-O in critical paths. Mere interpretive overhead won't do it. > Finally, you haven't addressed the remainder of the reasons I itemized. They were too obvious, describing problems that competent software engineers know how to prevent or hedge against, and you addressed me as though I were a n00b that just fell off a cabbage truck. My earliest contributions to Emacs were done so long ago that they predated the systematic Changelog convention; have you heard the expression "teaching your grandmother to suck eggs"? My patience for that sort of thing is limited. -- Eric S. Raymond