From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Drew Adams Newsgroups: gmane.emacs.help Subject: RE: [External] : Re: Is there a way of setting a variable only when it exists? Date: Tue, 15 Mar 2022 15:33:53 +0000 Message-ID: References: <87lexdul8e.fsf@mbork.pl> <878rtcir1h.fsf@zoho.eu> <87a6drviwp.fsf@mbork.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="21255"; mail-complaints-to="usenet@ciao.gmane.io" Cc: "help-gnu-emacs@gnu.org" , Emanuel Berg To: Jean Louis , Marcin Borkowski Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Mar 15 16:44:27 2022 Return-path: Envelope-to: geh-help-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 1nU9LP-000575-Tk for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 15 Mar 2022 16:44:20 +0100 Original-Received: from localhost ([::1]:56714 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nU9LO-0006Lm-CR for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 15 Mar 2022 11:44:18 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:41724) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nU9BU-0004D8-5G for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 11:34:04 -0400 Original-Received: from mx0a-00069f02.pphosted.com ([205.220.165.32]:29060) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nU9BR-0001bc-46 for help-gnu-emacs@gnu.org; Tue, 15 Mar 2022 11:34:03 -0400 Original-Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 22FFRocN000738; Tue, 15 Mar 2022 15:33:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-transfer-encoding : mime-version; s=corp-2021-07-09; bh=KoR7pCCJBeNM/yUyiVidPM10cBdrSTuE4bhZ7iRYz60=; b=tIpbswgpaAMIwuTaMDylde16ccV7S5I4E3VrKWpWJuEGJKohCJH2eUwypmHikYLTvfvf CgOONddnDbVW4MiZuIpEb/1Z+p6/LNnVtC+/kjju3QYs4PSwG0pNshk+E5b1RZIk7kTa BMNQQfNtvtJH/yBZDUGL64tIOnEMi2Nc9FR5xH7H/2dAFPBNxMYtZbzuzcyUaGFvVQg8 9KnZ7Ln+voMOt7h+kCMJJLHBEDVweUFwjbaG5Nsx9yySzmVd8MfxT9XVdHg7LNP0t1+S pakUuLmAS1mogS7O8cWxAawGpdKxY0ew9ewXHpwmBoaehalj2S/CokW6CUAfRMDcnlGe qQ== Original-Received: from userp3030.oracle.com ([156.151.31.80]) by mx0b-00069f02.pphosted.com with ESMTP id 3et5fu3m11-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 15 Mar 2022 15:33:57 +0000 Original-Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.1.2/8.16.1.2) with SMTP id 22FFV51k105254; Tue, 15 Mar 2022 15:33:56 GMT Original-Received: from nam11-co1-obe.outbound.protection.outlook.com (mail-co1nam11lp2171.outbound.protection.outlook.com [104.47.56.171]) by userp3030.oracle.com with ESMTP id 3et65pnu71-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 15 Mar 2022 15:33:56 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Pq0xP+vcBWBUsG4yu+FzY1dxVeAnYe4nDL5YvaVFUrZ/lqy3GoV0VkFO1BHkZbjxwnrWFDUpE+bpSkVEUqc5f+dzSLdr/DSn0QXTm8cyNoqDAgnX6/i2ARLqDH8jJs4d6bTp7Urnpw3bVvPh4a4DguGZBGmTvhoijs/O5sRRYXc2R2kxF60CcDA5VhwR+q+SzEfo9EfhCqkhZ1tqMBdyvijdISzjON4SmWn9LahM62xDlyFp8DXmr6PkawvjHtAC0SuH8bVnd5Uyb6OJ1HBuOekys76L7Wea+soSeGVZas/mk/nyYGIwEcYgC3HaZf33s/sjooh2uLiUXOkHnlbYzQ== 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-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=KoR7pCCJBeNM/yUyiVidPM10cBdrSTuE4bhZ7iRYz60=; b=ZTlBPx7PIwF+EvVBx0+IFp+qp7huDI7cR6Yxf4X1om9k9wSe5DRbBhD5r/r7AEN1qDllIqOI+GJrtseWefEynimXH//R5Zl3eUlzkIZzGZ+N1ilS5K9egQI6UqLDdTGVhpWItlo754W8Zx2ikbiGpZPFs6rt3LmlQECIPxBKpD7P0zaWHUtImmJWzOxamCKNjlFNRCoFDXSF4r5rqOMEs2JUygtOKIYOS1PREG0bYpRrnZXamADexqrhDE4w0W03xs0MzuN6Cikc0aDhEGl+jFm0TCloqCCzsR8y0IBOh1uqpYYWg1lDB/44GggyO+D+xGosxeWV5FGWQryyLDWdHg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=KoR7pCCJBeNM/yUyiVidPM10cBdrSTuE4bhZ7iRYz60=; b=PLVn1BKRStqV2JI+B2hCuHn2XIVRTyY+ZkXWeds+LqYMBKUONmhfoDPwP33iOhGwVLXcgppaS3/NNpajSugaToRgtk3A8Edq8l1sHuKWQVx4XY3HXY7J2L8Z231fpwc6CSrIhPU2iTYRAOw3gxhIC6r09fXvRCJwR1dOColCA1U= Original-Received: from SJ0PR10MB5488.namprd10.prod.outlook.com (2603:10b6:a03:37e::19) by BN6PR1001MB2307.namprd10.prod.outlook.com (2603:10b6:405:35::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5061.28; Tue, 15 Mar 2022 15:33:53 +0000 Original-Received: from SJ0PR10MB5488.namprd10.prod.outlook.com ([fe80::ec69:8077:89b0:4379]) by SJ0PR10MB5488.namprd10.prod.outlook.com ([fe80::ec69:8077:89b0:4379%7]) with mapi id 15.20.5081.014; Tue, 15 Mar 2022 15:33:53 +0000 Thread-Topic: [External] : Re: Is there a way of setting a variable only when it exists? Thread-Index: AQHYODs/ctxnGNAJI0a8Y6NGOAER3qzAkqsw In-Reply-To: Accept-Language: en-US Content-Language: en-US x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: a19b6984-792a-48ab-65db-08da06993659 x-ms-traffictypediagnostic: BN6PR1001MB2307:EE_ x-microsoft-antispam-prvs: x-ms-exchange-senderadcheck: 1 x-ms-exchange-antispam-relay: 0 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 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 x-forefront-antispam-report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:SJ0PR10MB5488.namprd10.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230001)(366004)(110136005)(186003)(76116006)(316002)(33656002)(54906003)(38100700002)(26005)(66946007)(122000001)(38070700005)(6506007)(71200400001)(2906002)(7696005)(9686003)(44832011)(4744005)(86362001)(55016003)(8936002)(508600001)(5660300002)(64756008)(66476007)(66556008)(66446008)(4326008)(52536014)(8676002); DIR:OUT; SFP:1101; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?utf-8?B?ZDFGT3MybnhvMUZsWkM2b3RFQUNmUEsrQlg5Q21qMDdtRmtQb24zd3RnQUZz?= =?utf-8?B?eGxFMXQzeXlGemNNUUtGeU8rZ2NCUWFzK09kZTV2RUxhY2d3OXRWZmZYTnlZ?= =?utf-8?B?c0h2S2V3Smh5OExoYWI1MlNwV0hoUjRDby9RcUdqMXluZnM5NnZrZmdZZEU2?= =?utf-8?B?Wjk3WmpPY2NDR1ZxVVM2SHpJNkFGWUI1QStiNVBITmlRQlhhODltUE9QQkhk?= =?utf-8?B?NTE2Z1dvdE9JOHN5UnhSblJidGtscytHcE1xYlRDaHlPLy8rS2hTTHB6Y0pY?= =?utf-8?B?YTJQQk1nN2tTNWNtSGpDbFZ1UWdyRTRQRWFld1cvb3B1MFdyaGVTWVhyNkZC?= =?utf-8?B?MEdDY2hNaG9lOWRJV2RFZ0EvamtsNVJlb0UyREVWNG1URmhPRHF0ZlVRekhC?= =?utf-8?B?NndYTUcvREMvVEcyS1Qrd3R1eUdrWmpLVXJoQWhibzRxTnl0WmRnZ1lML2Q0?= =?utf-8?B?T0NPN0kwZ3ZqRCtCVWs0T3AzWmo2Z1h2dGFyS1FKQkZLY3RsUVVJUnZMT3dL?= =?utf-8?B?NmkraHBWTHdwSzR6bjkzM1V6OUhPMFRNZExuSVg2YVhQeERwQkZxWFR2Q2Mr?= =?utf-8?B?MHZRd25pOHFJMmsxaWxJdCtjdWNOMzQ2ZS9ZQVFMT3c3UmxBK3NielQzY2d3?= =?utf-8?B?c1FHdmZKaHl2UWRkY3lxem9HMzFid21qeXdsdD X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SJ0PR10MB5488.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: a19b6984-792a-48ab-65db-08da06993659 X-MS-Exchange-CrossTenant-originalarrivaltime: 15 Mar 2022 15:33:53.7156 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: Q6Cd2Oa9u5xV7gMvL+Jp997Gkb5/X55ChgnJ8isbqZnglwwPf4G8ijOeGmlc2ebXObR1tEyIYtvjcFza1TqIPA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN6PR1001MB2307 X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10287 signatures=693139 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=876 phishscore=0 suspectscore=0 adultscore=0 spamscore=0 bulkscore=0 malwarescore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000 definitions=main-2203150101 X-Proofpoint-GUID: G5Nwk2DdxkkSMV0ZS4QZei5twMjrlmBr X-Proofpoint-ORIG-GUID: G5Nwk2DdxkkSMV0ZS4QZei5twMjrlmBr Received-SPF: pass client-ip=205.220.165.32; envelope-from=drew.adams@oracle.com; helo=mx0a-00069f02.pphosted.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, 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=ham autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:136587 Archived-At: PiAtIHdoYXQgaXMgdXNlciBvcHRpb24/DQoNCkMtaCByDQpnIEdsb3NzYXJ5DQpDLXMgVXNlciBP cHRpb24NCg0KICBVc2VyIE9wdGlvbg0KICAgICBBIHVzZXIgb3B0aW9uIGlzIGEgZmFjZSAocS52 Likgb3IgYSB2YXJpYWJsZSAocS52LikgdGhhdCBleGlzdHMgc28NCiAgICAgdGhhdCB5b3UgY2Fu IGN1c3RvbWl6ZSBFbWFjcyBieSBzZXR0aW5nIGl0IHRvIGEgbmV3IHZhbHVlLiAgKk5vdGUNCiAg ICAgRWFzeSBDdXN0b21pemF0aW9uOjouDQoNClBlcnNvbmFsbHksIEkgdGhpbmsgdGhhdCBkZWZp bml0aW9uIGlzbid0IHVwLXRvLWRhdGUuDQoNCk1vc3QgcGxhY2VzIGluIEVtYWNzLCAib3B0aW9u IiwgYWthICJ1c2VyIG9wdGlvbiIsIGFrYQ0KInVzZXIgdmFyaWFibGUiLCBha2EgImN1c3RvbSB2 YXJpYWJsZSIgbWVhbnMgd2hhdCB5b3UNCmNhbiBjdXN0b21pemUgdXNpbmcgYE0teCBjdXN0b21p emUtb3B0aW9uJy4gIFRoYXQgaXMsDQpmYWNlcyBhcmUgbm90IG5vcm1hbGx5IGNvbnNpZGVyZWQg b3B0aW9ucy4NCg==