From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Arthur Miller <arthur.miller@live.com> Newsgroups: gmane.emacs.devel Subject: Docs for &optional and &rest arguments together Date: Tue, 29 Dec 2020 14:26:32 +0100 Message-ID: <AM0PR06MB657709C899365FC0710F505496D80@AM0PR06MB6577.eurprd06.prod.outlook.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="29864"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Dec 29 14:42:28 2020 Return-path: <emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org> 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 <emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org>) id 1kuFGd-0007f4-Q3 for ged-emacs-devel@m.gmane-mx.org; Tue, 29 Dec 2020 14:42:27 +0100 Original-Received: from localhost ([::1]:40404 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from <emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org>) id 1kuFGc-0006UI-Qh for ged-emacs-devel@m.gmane-mx.org; Tue, 29 Dec 2020 08:42:26 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:39006) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <arthur.miller@live.com>) id 1kuFFt-0005lI-Mv for emacs-devel@gnu.org; Tue, 29 Dec 2020 08:41:42 -0500 Original-Received: from mail-am7eur06olkn2053.outbound.protection.outlook.com ([40.92.16.53]:41953 helo=EUR06-AM7-obe.outbound.protection.outlook.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <arthur.miller@live.com>) id 1kuFFr-0007wK-Fi for emacs-devel@gnu.org; Tue, 29 Dec 2020 08:41:41 -0500 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=G0ZCvtPfoYeoQx7NG4rQbrt/6aeGTxRK6g0e1O7XIR3/ay835++I42oHvCuXq2s1w7zR5DV1BBe+I664bCiTBQ4DC1MBV96jsT3Uhc31/9HcoG16IW7jY6QFOOps54QkH0BqXhI2rGFv0O9pUup/VeIMQ1jvL+il0HP4ZzKyZk6U8c1k8Z19IfR382fRFgdZJxePvFseGjLIUKlXzfHByDM3RemuZPDGwhMl4Kxx9ufhq9pDvmdrEMNMZ4HeW4IFAcdvQ5R8WzhUQBOBdzgHQpcB2oHbZwKiM3HU8LPwQs2gILljbMjTLtMRnlIcPr5/tcVprf0M+o1GZeW0a6J6Gw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=1+63RiI+JjnP1qi8FM/U68uplMYIb0UPcmnPv6lD6No=; b=cvxXTJ3SIxcJsZqws4fYeFDquWOVskkKqyl3BLvOLLkk+xWacDIl16FpeQvjiQ6SjJctirTJ/iVmZ1jMm3w0fTqG33UAp4lryrsAXuMMX6FPvcTBIKul7tZduT20i6PYl/H/kUZM760o2FhuShSKAT0DiGxMIopBypzlyxOOuEBpOyBxJZPAOUNdhuVag05NkML5y58tJ+e201n2o7R27FvPb6cI+hycm+Qf23g+MU0r9JosjFnPeTDxE/AqheSpnK1PHV3Hca7mu+3Ln+PJytc5PoyP4wLss5gX4OZqf9XSREET1HOjiUOUuQ6dMff+8eRqOP986I9iN0EhqADEyw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=live.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=1+63RiI+JjnP1qi8FM/U68uplMYIb0UPcmnPv6lD6No=; b=ZIcpIn4PZv8psH7Lkfov06ExcfZB+JAvBFHDHH5AfZq3ZgH/QzexPB8jmrjgljbv/XeDa/BxavS49LDoHZKLiwGDa/BvjS/7dcCNb4oSNbQvLvTbhj4dVr5CStju/qOJ4YltRzfHEDQR/Edk3FDOoXYDpWyWhJi5XeSVCsCGRiFTE9BDkB7Ug76lk7JmvEuT54V8HGta/XRJst20g7VgRrOBePDH5bovzJGGQ9Ic3rmDqpa9ufSnC55157mn9frNFSEa4Z4p7W/J6Difcz1gqn12LQrxVS+l3WWxP4HD2KtDRqNdnCxgabSFtG9yILaNmAXIJVthkziEWn9nYdI+FQ== Original-Received: from AM7EUR06FT026.eop-eur06.prod.protection.outlook.com (2a01:111:e400:fc36::51) by AM7EUR06HT075.eop-eur06.prod.protection.outlook.com (2a01:111:e400:fc36::73) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3700.27; Tue, 29 Dec 2020 13:26:33 +0000 Original-Received: from AM0PR06MB6577.eurprd06.prod.outlook.com (2a01:111:e400:fc36::52) by AM7EUR06FT026.mail.protection.outlook.com (2a01:111:e400:fc36::393) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3700.27 via Frontend Transport; Tue, 29 Dec 2020 13:26:33 +0000 X-IncomingTopHeaderMarker: OriginalChecksum:18AB71676E6A826A60831B93E36C43843180863331B6D66E96BF2E63767CFAA8; UpperCasedChecksum:D81BD8A22CB18861FFEDF6B29694C42215C95C43E0E1063590DB91CB408802F6; SizeAsReceived:8389; Count:44 Original-Received: from AM0PR06MB6577.eurprd06.prod.outlook.com ([fe80::9487:8c7d:da00:4993]) by AM0PR06MB6577.eurprd06.prod.outlook.com ([fe80::9487:8c7d:da00:4993%7]) with mapi id 15.20.3700.031; Tue, 29 Dec 2020 13:26:33 +0000 X-TMN: [4wiLbKGr2Xpz1U2rX57v6LjiIoRTYMpI] X-ClientProxiedBy: AS8PR04CA0261.eurprd04.prod.outlook.com (2603:10a6:20b:330::26) To AM0PR06MB6577.eurprd06.prod.outlook.com (2603:10a6:208:19a::23) X-Microsoft-Original-Message-ID: <87y2hg3fqv.fsf@live.com> X-MS-Exchange-MessageSentRepresentingType: 1 Original-Received: from pascal.homepc (90.230.29.56) by AS8PR04CA0261.eurprd04.prod.outlook.com (2603:10a6:20b:330::26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3700.30 via Frontend Transport; Tue, 29 Dec 2020 13:26:32 +0000 X-MS-PublicTrafficType: Email X-IncomingHeaderCount: 44 X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-Correlation-Id: 36ea20e5-94ad-4609-75cc-08d8abfd5c0e X-MS-TrafficTypeDiagnostic: AM7EUR06HT075: X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: DXZ0wl2w3sSJk3XM+0vWf3vVv86ZgPDTYHKzAsjG9trGniYM0515If4cvqI+hZAq+wWXFXEVaJN47wagHQw5CSc1vu325xmZB99QJJZgo0XNuOYZ+Pjt7aaKDI/i66V2U3rbu0/exxF39S2guoJ3O6iMof+4k3YmPfVupDvmpLg2dfMUjvpiiznXWMsFbd3Iq5778dDzjgKYxxrULF/wXjWGrxsOvm/G4/BE/BhmVToUfLdabD1CdABwDBW2zHlgsKNUQzkNa1j5SMOl/2M5Ah36sqooe8C0zUzxEU1PBqQ= X-MS-Exchange-AntiSpam-MessageData: RQoKa45Q2vK+5LB7sI4NM+AkV/5ckW3aURT0Y6x3z0vTdbJomZ89+O9Vy0OcuWwTeG+d3fOSNetAi8k6YN4eKmgVBW0KGF4ApEEUPm1aQvxSxopmslKMMRIobb5XLdV1VqzEgbzm6B3eWryQCJZ2/A== X-OriginatorOrg: live.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Dec 2020 13:26:33.1835 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-CrossTenant-Network-Message-Id: 36ea20e5-94ad-4609-75cc-08d8abfd5c0e X-MS-Exchange-CrossTenant-AuthSource: AM7EUR06FT026.eop-eur06.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: Internet X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM7EUR06HT075 Received-SPF: pass client-ip=40.92.16.53; envelope-from=arthur.miller@live.com; helo=EUR06-AM7-obe.outbound.protection.outlook.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, FREEMAIL_FROM=0.001, MSGID_FROM_MTA_HEADER=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_PASS=-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." <emacs-devel.gnu.org> List-Unsubscribe: <https://lists.gnu.org/mailman/options/emacs-devel>, <mailto:emacs-devel-request@gnu.org?subject=unsubscribe> List-Archive: <https://lists.gnu.org/archive/html/emacs-devel> List-Post: <mailto:emacs-devel@gnu.org> List-Help: <mailto:emacs-devel-request@gnu.org?subject=help> List-Subscribe: <https://lists.gnu.org/mailman/listinfo/emacs-devel>, <mailto:emacs-devel-request@gnu.org?subject=subscribe> Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" <emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org> Xref: news.gmane.io gmane.emacs.devel:262065 Archived-At: <http://permalink.gmane.org/gmane.emacs.devel/262065> I like 'with-*' idiom in Lisp, and I have written a smal macro for myself to work with files, based on with-temp-file macro. The Manual says I can have both optional and rest arguments togheter, which we can:=20 (required-vars=E2=80=A6 [&optional [optional-vars=E2=80=A6]] [&rest [rest-var]]) But when I use it, I still have to pass a nil for the "optional" argument, which I think is also not so strange either, otherwise how will Emacs now where "optional" argument list ends and where "rest" argument list starts? No? When I read the manual: "A call to the function requires one actual argument for each of the required-vars. There may be actual arguments for zero or more of the optional-vars, and there cannot be any actual arguments beyond that unless the lambda list uses &rest. In that case, there may be any number of extra actual arguments. If actual arguments for the optional and rest variables are omitted, then they always default to nil." https://www.gnu.org/software/emacs/manual/html_node/elisp/Argument-List.htm= l I get the impression that I actually can omit the optional argument(s) even when followed by the &rest keyword. It is probably only the case when optional arguments *are not* followed by the &rest keyword. I don't see that captured by the documentation, at least not very clearly. After the experience with add-to-list I am not offering any patches for the docs. I am just pointing it out how I perceive it. If I am wrong about, I would be actually happy to see how to use both &optional and &rest and not have to specify the "optional" argument when I call the macro= . For the illustration of what I describe above, here is the macro: (defmacro with-file (file &optional operation &rest body) (declare (indent 1) (debug t)) `(let ((op ,operation) (buffer (get-buffer-create ,file))) (unless op (setq op 'append)) (unwind-protect (prog1=20 (with-current-buffer buffer (cond ((equal op 'apend) (goto-char (point-min)) (insert-file-contents ,file) (goto-char (point-max)) ,@body) ((equal op 'prepend) ,@body (goto-char (point-max)) (insert-file-contents ,file)) (t ;; overwrite file ,@body))) (with-current-buffer buffer (write-region nil nil ,file nil 0))) (and (buffer-name buffer) (kill-buffer buffer))))) And when calling, there is no way to omit the "optional" nil: (with-file "some-test" nil (insert "hello world")) (with-file "some-test" 'prepend (insert "I am before Hello world!") (newline)) (with-file "some-test" 'apend (newline) (insert "I am after Hello world!"))