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: Installing cond* in core Date: Fri, 02 Feb 2024 08:17:25 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="6745"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: emacs-devel@gnu.org To: Richard Stallman Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Feb 02 14:18:15 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 1rVtQt-0001W5-5l for ged-emacs-devel@m.gmane-mx.org; Fri, 02 Feb 2024 14:18:15 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rVtQE-00084h-0s; Fri, 02 Feb 2024 08:17:34 -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 1rVtQB-00084J-Jy for emacs-devel@gnu.org; Fri, 02 Feb 2024 08:17:32 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rVtQ9-0001ET-8Q; Fri, 02 Feb 2024 08:17:30 -0500 Original-Received: from pmg1.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg1.iro.umontreal.ca (Proxmox) with ESMTP id 16127100390; Fri, 2 Feb 2024 08:17:27 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1706879846; bh=CKoBWHednt9AnPW2/oF2Z9D5Im1ouuF5tL2OrMfSOQk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=Z3kHah36COWhYfeSl1KyC/ATDl4ZjX2jzWt6nzjymTW+BLpleJSo1z0qBGviNYzCE lF8PCD9RjKLIlRZo1tZGtuqA/0W+x/bFsvPqERSRWqJpAi9dtPxmU33tXgMrCFRewK 5EBtssDo8pUgPgNFm7zAbC6+Rkkib3qTImzTsroxMgRd6lZp6aY1Lpf1gKVd3vCIVk ob1iT1wwFvULRfLHMSoRJ/C19GM964Tq08RDiwubEE7dbgHYlfxv+wEmCsrwIPod0E Sqqi+3rjo1twlmhFCkQ0NNrOwclOvZFwPGpQk38PIHITM+h2KLloN3dSRTdiTVIwQC 3QjzAQV73rDGQ== Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg1.iro.umontreal.ca (Proxmox) with ESMTP id 1411A100302; Fri, 2 Feb 2024 08:17:26 -0500 (EST) Original-Received: from pastel (69-165-153-17.dsl.teksavvy.com [69.165.153.17]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id E44CE120B52; Fri, 2 Feb 2024 08:17:25 -0500 (EST) In-Reply-To: (Richard Stallman's message of "Thu, 01 Feb 2024 22:39:16 -0500") 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-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:315744 Archived-At: > > I think the question is rather: why should we have two equivalent and > > almost identical matching syntaxes and implementations? > That is the easiest way to make cond* function. Only if you consider "easiest" at each small incremental step. The overall cost of what you've done is already much higher :-) > I do not understand the pcase code for implementing pattern matching, You don't need to understand it. > A priori, I suspect it won't fit. cond*-subpat, which does this job > in cond*, passes data up and down the recursion. I can't tell whether > pcase does something comparable. Also, cond*-subpat does not generate > the overall structure of a clause -- its caller, cond*-match, does > that. Throw away cond*-subpat. Just rewrite (cond* ((match* PAT FORM) THEN) . ELSE) into something like (pcase FORM (PAT THEN) (_ (cond* . ELSE))) And presumably for (cond* ((match* PAT FORM)) . REST) you'd rewrite it to (pcase-let ((PATH FORM)) (cond* . REST)) No need to look inside or understand `pcase.el` at all! Stefan