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.devel Subject: Re: cond* Date: Mon, 08 Jan 2024 15:26:09 +0000 Message-ID: <87ttnnyhgu.fsf@localhost> References: <87frzuae9n.fsf@posteo.net> <871qbatqc8.fsf@posteo.net> <87wmsz7lzn.fsf@posteo.net> <87edf1m7lq.fsf@localhost> <87il4a76zw.fsf@localhost> <871qauwquc.fsf@localhost> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="38624"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: rms@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Jan 08 16:23:31 2024 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 1rMrTO-0009tk-Ir for ged-emacs-devel@m.gmane-mx.org; Mon, 08 Jan 2024 16:23:30 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rMrT6-0007n9-9N; Mon, 08 Jan 2024 10:23:12 -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 1rMrSz-0007Zv-2n for emacs-devel@gnu.org; Mon, 08 Jan 2024 10:23:08 -0500 Original-Received: from mout01.posteo.de ([185.67.36.65]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rMrSu-0006Lo-VY for emacs-devel@gnu.org; Mon, 08 Jan 2024 10:23:04 -0500 Original-Received: from submission (posteo.de [185.67.36.169]) by mout01.posteo.de (Postfix) with ESMTPS id 68B7D240027 for ; Mon, 8 Jan 2024 16:22:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1704727377; bh=m+1ppNWHrf/wbEFKM4asmOJhtzn4cYkUr1E36d8Tjiw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:From; b=rJjTRFR730J1FCx6u1Y7CPTCo/FtlC1hcBnewouPKs1/rnIvjXi72DzM94f5mXqLa bg5L0KJ0i0zE4iobf5KaxPk4EOOytV46ANkB8GSvc+3IlJUAaA/Xe/zJJrlRyD61Vw m4BLleRJn5AHFsknyp8SH1xDcoucyGz04z60CDOkVBLiSLZ8xulV1u+E9ESF64FIpM iPiX9y/rFZGgDNz+fJKSlohGlWb0qpYsnE+9/mn+qzUmxhvjmt2UI92i6vyOwelZcl Y0+u/pbGQAoZQcIB1d1qUb9lsmeah7d7yNTT/EnW4k01cWqW14Wpc4bZ/TSCWpFMZU Bx1x+9d0yjrgw== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4T7yVm4kcGz9rxD; Mon, 8 Jan 2024 16:22:56 +0100 (CET) In-Reply-To: Received-SPF: pass client-ip=185.67.36.65; envelope-from=yantar92@posteo.net; helo=mout01.posteo.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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:314749 Archived-At: Richard Stallman writes: > > May you please elaborate how you see named variables in `rx'? > > Exactly the same as in `rx' in pcase. > > I suppose pcase transforms the (rx ...) construct into a regular > expression -- right? If this can be implemented for the (rx ...) > pattern in pcase, it can be implemented for `rx' the function with the > same code -- right? > > I expect it would work by allocating a subpattern number for each > (let ...) variable. > > Please don't tell me that someone reimplemented `rx' from scratch > for pcase, rather than using the existing `rx' code! The way (let ...) expressions are handled inside pcase is defined in `rx--pcase-expand'. It has nothing to do with rx operation itself. Instead, it parser the rx pattern, and transforms it into a different pcase match: This (pcase " #+begin: something" ((rx line-start (0+ (any " \t")) "#+BEGIN:" (0+ (any " \t")) ;; matches "something" ;; (let VAR ) binds VAR to sub-expression match. (let matched-value (1+ word))) (format "We just matched \"%s\"" matched-value))) becomes something along the lines of (pcase " #+begin: something" ((app (lambda (s) (and (string-match regexp-generated-by-rx s) (list (match-string 0 s) (match-string 1 s)))) `(_ ,matched-value)) In other words, `rx' pattern matching is implemented by rewriting the pattern using other `pcase' constructs during macro expansion. The original `rx' is not changed and does not assign any variables. -- Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at