From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: steve-humphreys@gmx.com Newsgroups: gmane.emacs.help Subject: Re: Appending to a list Date: Sun, 13 Dec 2020 22:46:09 +0100 Message-ID: References: <877dpljtwg.fsf@fastmail.fm> <87sg89v1f7.fsf@telefonica.net> 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="33502"; mail-complaints-to="usenet@ciao.gmane.io" Cc: help-gnu-emacs@gnu.org To: =?UTF-8?Q?=C3=93scar_Fuentes?= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sun Dec 13 22:46:44 2020 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 1koZCW-0008d0-Au for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 13 Dec 2020 22:46:44 +0100 Original-Received: from localhost ([::1]:53350 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1koZCV-0007FK-Bz for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 13 Dec 2020 16:46:43 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:59722) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1koZC5-0007DE-Sx for help-gnu-emacs@gnu.org; Sun, 13 Dec 2020 16:46:17 -0500 Original-Received: from mout.gmx.net ([212.227.17.20]:58403) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1koZC0-0006gO-4E for help-gnu-emacs@gnu.org; Sun, 13 Dec 2020 16:46:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1607895970; bh=EDl1HwE6sOkg972GBSD2gs36eB0A2Bpbd92lTQO5tME=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=fWdsNtOL9kiYO75ct63M7RejHoDwaqIt4W/qxeL2wXptJT8WaBjbfWdARCXbvd1L/ By+3gNE1TkeEPHovKa6efnFqWfFrS1W/LR3CseqVgDF99sZsMjHFH/Y27Xdzh0hiby DixhrzflNZJ7XvFHy3b06aiVj6oSOSCeHmUoafus= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Original-Received: from [213.165.168.94] ([213.165.168.94]) by web-mail.gmx.net (3c-app-mailcom-bs09.server.lan [172.19.170.177]) (via HTTP); Sun, 13 Dec 2020 22:46:09 +0100 Importance: normal Sensitivity: Normal In-Reply-To: <87sg89v1f7.fsf@telefonica.net> X-UI-Message-Type: mail X-Priority: 3 X-Provags-ID: V03:K1:pXqxsnmom9MO8wuc9xJWukk0U1J0olOtjS6JJMd3OqJrMQ8+GmSVVp/iOSonlBZKhH2XM /G3Lc7Uz0eJFnRkqTokwMRS7yTJckGN2m4XTi7YRE8c7AdTi7ifjUg5PEC4VBVj3wOiWG7S7u63u v3Fd1TrZTxWzOOdHvxyB2KNsAjEuX5KMuyXs3ferctMyvCo7MharodWTilQfUSCYKPKY9CE2Zoyi glMjTQnB9isREhOJnK0o3RsTy9rl94mY0jm6+toBu9T21+X14yzSDTVPlOLSGEql1grevJ5Glj4W Dk= X-UI-Out-Filterresults: notjunk:1;V03:K0:sKUpyG/8VXE=:jgzKILJSL/9RMbwk46EPjV JtfXrXp6bqTwATG9GEKxX8/W4ZL5p7WgRXy9yd0KZwYTucDkaqbbm4uRYtEX+lXvxyPamamv7 63w8CuQ4qWBwT14WCNmh2M3XCp6oJuHsq3gcL50saudvEreOLh9IaN0jMjxct3W01EXMQaobF EAhTTduv++sjSBlyLEcVvSavhp1LzatmVa4X/F+mwZs59oq8l8Pte9nVUEx5pWupNoW2fVP8e RuHcWUx/ebsHyBVtrBaQjOV4vOONSISAAX6Izlh3oqlnadG14h91C7leJteVEpS3UNg3GHYIL Tjo5Ipz7Hu+1yIDpK9NOWV1NKUffVV5hZ0xSGo4tYYn77LY9PH9SjALxC5o5hNqRBPwA0uTZV ENw+Ll0jtE8vHTvVM5uawBkJul67iZnV4R0AGIWgvSd1rHNEVNU9Rusn+tzw0LelQ+MeqU+wj MX4ZVztzETzG3u2P6CdI0rgas7RnCoyusvfVuJUF9+oosMJodLZOvJjP5vD/rREznOzMrLRuj L6qlcikihRbxyBjDdcxvU9MjX7Ghyj6MV20uFYC9d4/XphrtGEHBqBJW99UdFVZ2HcRYqKvr6 42STKmSRl0UpI= Received-SPF: pass client-ip=212.227.17.20; envelope-from=steve-humphreys@gmx.com; helo=mout.gmx.net X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 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:126328 Archived-At: > Sent: Sunday, December 13, 2020 at 10:30 PM > From: "=C3=93scar Fuentes" > To: help-gnu-emacs@gnu=2Eorg > Subject: Re: Appending to a list > > Joost Kremers writes: >=20 > > On Sun, Dec 13 2020, steve-humphreys@gmx=2Ecom wrote: > >> Would appending to list like this be good? > >> > >> (setq bird '("Toucan" "King Fisher")) > >> (setq bird (append bird ("Swift") )) Can one just append lists together, then store the result to one of the va= riables, as I did? =20 Or could such an approach lead to unintended consequences in some circumst= ances? Regards Steve > > This should result in an error, because `("Swift")` isn't quoted=2E Yo= u'd need: > > > > (setq bird (append bird '("Swift"))) > > > > But note that the last argument of `append` isn't copied, so it may no= t be a > > good idea to use a literal list=2E > > > >> Or does one customarily use other constructs for > >> adding to a list? > > > > `push` is what I would use: > > > > (push "Swift" bird) >=20 > This does not append=2E >=20 > > No need to use `setq` here=2E > > > > `push` won't check if the element is already in the list, though=2E Yo= u can use > > `cl-pushnew` in that case, but be sure to load the library it's in: > > > > (require 'cl-lib) > > (cl-pushnew "Swift" bird) >=20 > Isn't that the same as >=20 > (add-to-list bird "Swift" t) >=20 > ? >=20 >=20 >