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.bugs Subject: bug#60953: The :match predicate with large regexp in tree-sitter font-lock seems inefficient Date: Mon, 30 Jan 2023 20:42:34 +0200 Message-ID: <83wn533lut.fsf@gnu.org> References: <7624dddc-4600-9a03-ac8b-d3c9e0ab618c@yandex.ru> <04729838-b7d4-8a08-2b71-12536a28aebb@yandex.ru> <83wn5ag4nc.fsf@gnu.org> <01b5d074-fb12-6b1f-cbfb-5e759833b854@yandex.ru> <838rhpg57n.fsf@gnu.org> <5026D975-983F-4D18-8690-BE139C92825D@gmail.com> <83pmb1emxi.fsf@gnu.org> <6f318afc-ca71-8b7e-c822-52e6635b5718@yandex.ru> <83sffxcfxw.fsf@gnu.org> <83pmb1cbg5.fsf@gnu.org> <2da844d3-ea31-289e-2821-aa174e365ffd@yandex.ru> <6784f9e7-844b-374d-2a1e-8a61cebe0d7e@yandex.ru> <83zga03yne.fsf@gnu.org> <373a575f-c683-1581-c3e6-502e9897fb04@yandex.ru> <83mt603vrc.fsf@gnu.org> <83e58a1b-2e4a-356a-36d8-c756ff105b62@yandex.ru> <83bkmf52va.fsf@gnu.org> <33cad4c1-4af5-37bb-05bc-79a4d9c1a700@yandex.ru> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="2873"; mail-complaints-to="usenet@ciao.gmane.io" Cc: casouri@gmail.com, 60953@debbugs.gnu.org To: Dmitry Gutov Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Mon Jan 30 19:43:45 2023 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1pMZ85-0000bG-0M for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 30 Jan 2023 19:43:45 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pMZ7h-0007le-JP; Mon, 30 Jan 2023 13:43:22 -0500 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 1pMZ7P-0007Zm-VQ for bug-gnu-emacs@gnu.org; Mon, 30 Jan 2023 13:43:06 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pMZ7O-0004nu-Ff for bug-gnu-emacs@gnu.org; Mon, 30 Jan 2023 13:43:03 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1pMZ7O-00035j-C5 for bug-gnu-emacs@gnu.org; Mon, 30 Jan 2023 13:43:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 30 Jan 2023 18:43:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 60953 X-GNU-PR-Package: emacs Original-Received: via spool by 60953-submit@debbugs.gnu.org id=B60953.167510417011864 (code B ref 60953); Mon, 30 Jan 2023 18:43:02 +0000 Original-Received: (at 60953) by debbugs.gnu.org; 30 Jan 2023 18:42:50 +0000 Original-Received: from localhost ([127.0.0.1]:50547 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pMZ7B-00035I-Kp for submit@debbugs.gnu.org; Mon, 30 Jan 2023 13:42:49 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:32958) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pMZ79-00034e-UP for 60953@debbugs.gnu.org; Mon, 30 Jan 2023 13:42:48 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pMZ74-0004dg-Du; Mon, 30 Jan 2023 13:42:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=lYR8aEeZdetOsZPsCuVf+Y150WL2e43FUhhXqz43rm0=; b=d+t5TOLL7gLk rDISKa5OI4/4NKSz7DECrfx8lRCgLRvKQtI8+cWsV93rXGZVe/ikRXMErVYcF4/RxYvjSGA7pRq7p TAx0HHYwIN2c8r4uEz1Vg8Whenb19tbGYExUf+QwVp3FF/QpUArewAn7h3blD19Wxm8lgmzNnoO6L Zd9o2o2JzWn65YDwyraqIbWe2gvSlD82emIP4zIkpHtInsG70uYY9TklHp6YHJlbgQE3xXYXC0Jnr HaQtYsWIkDJQR31FOOAO3Tyn0x/Ltx9ZO3kvMpvQrCQ3TYy0M73w0N9zlCOp/k4XMNNoWRnmQhlJB zsNSG//cVJTuI4+Vtu67XA==; Original-Received: from [87.69.77.57] (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 1pMZ72-0003cX-OK; Mon, 30 Jan 2023 13:42:42 -0500 In-Reply-To: <33cad4c1-4af5-37bb-05bc-79a4d9c1a700@yandex.ru> (message from Dmitry Gutov on Mon, 30 Jan 2023 20:20:46 +0200) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:254470 Archived-At: > Date: Mon, 30 Jan 2023 20:20:46 +0200 > Cc: casouri@gmail.com, 60953@debbugs.gnu.org > From: Dmitry Gutov > > On 30/01/2023 19:49, Eli Zaretskii wrote: > >> Date: Mon, 30 Jan 2023 19:15:07 +0200 > >> Cc: casouri@gmail.com, 60953@debbugs.gnu.org > >> From: Dmitry Gutov > >> > >>> fast_looking_at already does an anchored match, so I'm not sure I > >>> follow. I don't even understand why you need th \` part, when the > >>> match will either always start from the first position or fail. > >> > >> The regexp might include the anchors, or it might not. > >> > >> It might also use a different anchor like ^ or $ or \b. > > > > OK, but it always goes only forward, so narrowing to the beginning > > shouldn't be necessary. Right? > > Are you saying that fast_looking_at ("\\`", ...) will always succeed? > > And fast_looking_at ("^", ...), etc. For example, for "^", if you hint that it must look back to make sure there's a newline there, then your narrowing will also prevent it from doing that, right? > >> One possible alternative, I suppose, would be to create a raw pointer to > >> a part of the buffer text and call re_search directly specifying the > >> known length of the node in bytes. If buffer text is one contiguous > >> region in memory, that is. > > > > It isn't, though: there's the gap. Which is why doing this is not > > recommended; instead, use something like search_buffer_re, which > > already handles this complication for you. (Except that > > search_buffer_re is a static function, so only code in search.c can > > use it. So you'd need to make it non-static.) > > Interesting. Does search_buffer_re match the \` anchor at POS and \' at > LIM? IOW, does in treat the rest of the buffer as non-existing? Or could it? That is the low-level subroutine called by re-search-forward, so you know the answers already, I think? IOW, that function behaves exactly like re-search-forward in those situations.