From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Ideal performance of ELisp Date: Fri, 12 Aug 2022 22:11:21 -0400 Message-ID: References: <83o7wuva9o.fsf@gnu.org> <83mtceupbx.fsf@gnu.org> <83lerxvfnu.fsf@gnu.org> <838rnxvdcq.fsf@gnu.org> <83r11ptksn.fsf@gnu.org> <83a68dti6w.fsf@gnu.org> <874jykzvx9.fsf@yahoo.com> <83fsi4sttn.fsf@gnu.org> <838rnws5c7.fsf@gnu.org> <838rntocb8.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="23373"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) Cc: Eli Zaretskii , Po Lu , Alan Mackenzie , emacs-devel , Yuan Fu To: Lynn Winebarger Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Aug 13 04:12:12 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 1oMgdH-0005q2-HN for ged-emacs-devel@m.gmane-mx.org; Sat, 13 Aug 2022 04:12:11 +0200 Original-Received: from localhost ([::1]:33412 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oMgdG-0004mS-0Z for ged-emacs-devel@m.gmane-mx.org; Fri, 12 Aug 2022 22:12:10 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47548) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oMgcZ-000430-Tl for emacs-devel@gnu.org; Fri, 12 Aug 2022 22:11:27 -0400 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:54287) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oMgcX-0003Dt-Ix; Fri, 12 Aug 2022 22:11:26 -0400 Original-Received: from pmg3.iro.umontreal.ca (localhost [127.0.0.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 450FD4411A3; Fri, 12 Aug 2022 22:11:24 -0400 (EDT) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 2927244117F; Fri, 12 Aug 2022 22:11:23 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1660356683; bh=aoI15pwDdG/Wjo+Uu2Aae/m06HQJfk6aLo4NWu/H4KM=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=ZQmBcpfQtybTD6LCCNBUzBd1WTSIoW7p+CC0YUGY2y9PbUDoPnKdoAYVRcF9ZJDfi iazwv4MtoYpbV1XNwvi8c9HmRnweg78miKHp0Z3saa3aHNqvexbKmozVLC7RxZJRio 5vX57lxUwNacbEtuqUi+0qlTGCFiA52OfdW5EAkJai6+0jdxTc+qZr8tQhzefkaVcj BthXdn9RKr28b95x+7NyYZCBURwSoy7RHHI2m0P3f3FrvgqTIM73NWhZYdAJzSxCZ5 Vh3GCZc/Na2xdPGq/5LjwCBXWJnb1qVzuI8ixy8xjBLGhr6rwAtkQLV9RSpO8q3ffj N87kNPlp9smoA== Original-Received: from pastel (unknown [45.72.195.111]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id DFD7812039E; Fri, 12 Aug 2022 22:11:22 -0400 (EDT) In-Reply-To: (Lynn Winebarger's message of "Fri, 12 Aug 2022 19:26:14 -0400") Received-SPF: pass client-ip=132.204.25.50; envelope-from=monnier@iro.umontreal.ca; helo=mailscanner.iro.umontreal.ca X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" Xref: news.gmane.io gmane.emacs.devel:293399 Archived-At: > Once the VM supports proper tail recursion, it's straightforward to > generate automata that never perform a function call, at least not as part > of the recognizer. It was straightforward beforehand as well (using a `while` loop instead of recursion). And if you do use recursion, then it's not very much simpler with `lexical-binding` than without because you still have to take into account the possibility that the function gets redefined during your recursion :-( Don't get me wrong: `lexical-binding` is definitely very useful for native compilation (and it does help for tail-calls in some cases, e.g. in `named-let`), but I suspect that for the foreseeable future it'll stay hard to be competitive with something like tree-sitter when writing the code in ELisp. Stefan