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: How to add pseudo vector types Date: Tue, 03 Aug 2021 09:28:57 -0400 Message-ID: References: <83eeban40n.fsf@gnu.org> <83bl6en2ax.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="10981"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: Fu Yuan , stephen_leake@stephe-leake.org, cpitclaudel@gmail.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Aug 03 15:32:06 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 1mAuWb-0002ez-Vf for ged-emacs-devel@m.gmane-mx.org; Tue, 03 Aug 2021 15:32:06 +0200 Original-Received: from localhost ([::1]:40860 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mAuWZ-0002AB-B5 for ged-emacs-devel@m.gmane-mx.org; Tue, 03 Aug 2021 09:32:03 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47664) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mAuTh-0006fD-MV for emacs-devel@gnu.org; Tue, 03 Aug 2021 09:29:05 -0400 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:60242) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mAuTe-0003lN-Oe; Tue, 03 Aug 2021 09:29:04 -0400 Original-Received: from pmg1.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg1.iro.umontreal.ca (Proxmox) with ESMTP id 7D1D1100201; Tue, 3 Aug 2021 09:28:59 -0400 (EDT) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg1.iro.umontreal.ca (Proxmox) with ESMTP id 691A910001F; Tue, 3 Aug 2021 09:28:58 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1627997338; bh=aEM3tbW88mHn3pMpT8SaztzKtKUFA7f/4DGugW/zoqY=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=I848RnBiVx5Oz+hbDSN80/ziXt660j7KoMPp/IWmYdHwpAAv4eQ44+IAHgdWDUwCF YKjQao8z/TLQKbAQHk9hcA5J8AmFIyX+cWHTp5tWv/AFUfPpH2aGjrOlfkfbhYTNhv 6GLS4riV7z8LrmDLspINyWwuzx6RPp5qyBjOTiwwY7/n1cWKgKt3L/33zXnUOa85ws U2TDcZ1zU0tNMyuVMPLYJvANh74gUtcYP8cWTU7huUPzeoh7vJ1Psgwd6lru4fXx1r XbiFnDjElsIjnhkxKxkebGnoQ/G8MXlih8YO5wmPtcdPbGiXbpO3RRNfKVruQWxJ65 9Bj9A5GCXKuzg== Original-Received: from alfajor (unknown [216.154.29.138]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 2BF601204DE; Tue, 3 Aug 2021 09:28:58 -0400 (EDT) In-Reply-To: <83bl6en2ax.fsf@gnu.org> (Eli Zaretskii's message of "Tue, 03 Aug 2021 15:24:54 +0300") 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 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:271979 Archived-At: > But that's sub-optimal, no? Imagine a very large buffer which was > narrowed to a small portion near EOB, then a modification made very > close to EOB but partially before BEGV, then the buffer widened. With > your method, TS will now have to re-parse almost the entire buffer, > whereas we know it needs to re-parse a very small portion of it. As a general rule, we will most likely want to work hard to avoid exposing the narrowed buffer to TS (i.e. most calls to TS will first `widen`). Or we will want to keep several parse trees (one per narrowing). We have the same problem already with `syntax-ppss` which we solve by keeping two sets of data (`syntax-ppss-wide` and `syntax-ppss-narrow`). Stefan