From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ihor Radchenko Newsgroups: gmane.emacs.bugs Subject: bug#63225: Compiling regexp patterns (and REGEXP_CACHE_SIZE in search.c) Date: Tue, 09 May 2023 12:02:19 +0000 Message-ID: <871qjp1zn8.fsf@localhost> References: <63882A45-BD02-40D5-92FA-70175267BA3B@acm.org> <874jou7lsf.fsf@localhost> <37EED5F9-F1FE-46B6-B4FA-0B268B945123@gmail.com> <87wn1qqvj0.fsf@localhost> <34F4849A-CB39-4C96-9CC1-11ED723706DA@gmail.com> <87wn1psqny.fsf@localhost> <6DAF37F9-B236-4C33-8E30-0FCA47CCBCC5@gmail.com> <87zg6lfobh.fsf@localhost> <281B22C2-CD69-4495-A97C-E754446CA9A6@gmail.com> <87o7n1v1w3.fsf@localhost> <878E8D66-A548-42E6-B077-6068A8B131D8@gmail.com> <87ednvul22.fsf@localhost> <87y1m1oa01.fsf@localhost> <74CD5EF4-5424-40BA-8F80-D0FD89CB890F@gmail.com> <87zg6fjar6.fsf@localhost> <875y923964.fsf@localhost> <67AAB661-8B27-4D09-BF0D-6B76ABB54477@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="29493"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 63225@debbugs.gnu.org To: Mattias =?UTF-8?Q?Engdeg=C3=A5rd?= Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue May 09 14:00:19 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 1pwM0x-0007X9-Ja for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 09 May 2023 14:00:19 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pwM0j-00089T-IV; Tue, 09 May 2023 08:00:06 -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 1pwM0g-00088l-TT for bug-gnu-emacs@gnu.org; Tue, 09 May 2023 08:00:03 -0400 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 1pwM0g-0005H5-H9 for bug-gnu-emacs@gnu.org; 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Tue, 09 May 2023 07:59:09 -0400 Original-Received: from submission (posteo.de [185.67.36.169]) by mout01.posteo.de (Postfix) with ESMTPS id 47882240069 for <63225@debbugs.gnu.org>; Tue, 9 May 2023 13:59:02 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1683633542; bh=zh6PCkTSu/aGD4L6cgWpl4wuILXotDa4cV4/sddJiHM=; h=From:To:Cc:Subject:Date:From; b=VeEzdmoAyw4uMLUWCOOrWDRgWa1UfifO9n/fxZNzrBSHko50/zM07Govsak7seGzJ JSEIJ3mMaxF04xYXe78Bj6EafBUHEa1im2WR97FIdsCs1o6aWj8MP8NB7MoCrAb1kw rbCxELA617meQHdIDGV7Tsv3cmC+9ZhMFdmpJ+h6rsmYfffen0okzm7emh/TmOXMIa DOyveCuRU5gIY82ohdx4n0sqBhzeSToBQKkAARsFkFXpmT58Dcd25GAeZ9h15XW4YX Sa3jj8ffa2oodzsSfBRFjC3mvCnG8winFaR3cF2As4DDON2LTpIhHOwNR5ztXpDGCx LTwzf9vSXnd9A== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4QFxX557Q3z6tvr; Tue, 9 May 2023 13:59:01 +0200 (CEST) In-Reply-To: <67AAB661-8B27-4D09-BF0D-6B76ABB54477@gmail.com> 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:261405 Archived-At: Mattias Engdeg=C3=A5rd writes: > 8 maj 2023 kl. 21.38 skrev Ihor Radchenko : > >> Does this imply that simple regexps like >>=20 >> (looking-at-p (rx (seq bol (zero-or-more (any "\t ")) "#" (or " " eol)))) >>=20 >> should better be implemented as the following? > > Obviously this isn't practical or beneficial for any but the simplest pat= terns. Benchmark if you are concerned. > It is useful to know when (not) to use regexps. I did some benchmarking and your code does provide >2x improvement. Most of it is coming from using `forward-line' instead of `beginning-of-line'. I benchmarked different variations: (defun yant/test1 () (save-excursion (forward-line 0) ; faster than beginning-of-line (skip-chars-forward "[:blank:]") ; faster than looking-at-p (not (eolp)))) ; very cheap (defun yant/test2 () (save-excursion (beginning-of-line 0) (not (looking-at-p "[[:blank:]]*$")))) (defun yant/test3 () (save-excursion (beginning-of-line 0) (skip-chars-forward "[:blank:]") ; faster than looking-at-p (not (eolp)))) (defun yant/test4 () (save-excursion (forward-line 0) ; faster than beginning-of-line (not (looking-at-p "[[:blank:]]*$")))) - forward-line + skip-chars-forward :: (2.980 2 0.648) - beginning-of-line + looking-at-p :: (7.189 2 0.653) - beginning-of-line + skip-chars-forward :: (6.833 2 0.634) - forward-line + looking-at-p :: (3.180 2 0.663) >> I really hope that I did not need to do all these workarounds specific to >> current implementation pitfalls of Emacs regexp compiler. > > Some of them. We program for the system we have. Emacs is a very slowly m= oving target. Will it make sense to use a combination of char-after and skip-chars-forward every single time? I am thinking about something among the lines of (defconst org-fancy-re (propertize (rx bol (1+ "*") " ") 'org-re-direct '(progn (and (bolp) (> (skip-chars-forward "*") 0) (prog1 (eq ?\s (char-after)) (forward-char)))))) (define-inline org-fancy-looking-at-p (regexp) "Like `looking-at-p', but try `org-re-direct' property." (let ((sexp (and (inline-const-p regexp) (get-text-property 'org-re-direct (inline-const-val regexp))))) (if sexp (inline-quote (save-excursion ,sexp)) (inline-quote (looking-at-p ,regexp))))) >>> I would like that too, but changing that isn't easy. >>=20 >> I am sure that it is easy. > > I didn't mean technically. Code is easy to write. May you elaborate what is the blocker then? --=20 Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at