From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Jean Louis Newsgroups: gmane.emacs.help Subject: Re: Is there any existing solution to move list number backwards, forwards in a list? Date: Fri, 21 Oct 2022 18:54:32 +0300 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="22431"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/2.2.7+37 (a90f69b) (2022-09-02) Cc: help-gnu-emacs@gnu.org To: Stefan Monnier Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Fri Oct 21 18:03:15 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 1oluUL-0003w4-Ol for geh-help-gnu-emacs@m.gmane-mx.org; Fri, 21 Oct 2022 18:03:13 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oluSj-0002fp-20; Fri, 21 Oct 2022 12:01:33 -0400 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 1oluS0-0002Hy-76 for help-gnu-emacs@gnu.org; Fri, 21 Oct 2022 12:01:02 -0400 Original-Received: from stw1.rcdrun.com ([217.170.207.13]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oluRx-0005SY-1G for help-gnu-emacs@gnu.org; Fri, 21 Oct 2022 12:00:47 -0400 Original-Received: from localhost ([::ffff:197.239.7.218]) (AUTH: PLAIN admin, TLS: TLS1.3,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 0000000000055D52.000000006352C22B.00003728; Fri, 21 Oct 2022 09:00:42 -0700 Mail-Followup-To: Stefan Monnier , help-gnu-emacs@gnu.org Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=217.170.207.13; envelope-from=bugs@gnu.support; helo=stw1.rcdrun.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_SBL=0.141, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no 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: , Original-Sender: "help-gnu-emacs" Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:140245 Archived-At: * Stefan Monnier via Users list for the GNU Emacs text editor [2022-10-21 16:34]: > > Let us say item is number 7 in following list: > > > > '(1 2 3 4 5 6 7 8 9) > > > > Then I wish to move item number 7 to different number and renumber all > > items so that number 7 becomes number 6 and number 6 comes in the > > place of number 7. > > That was clear (ahem) :-) Thanks. You got it, though my expression is not perfect. > > Situation is more complex, > > I suspect so. From where I stand, the normal answer is to change the > priority of the relevant object and then to pass your list to `sort` > with the appropriate so it re-sorts based on the new priorities. I have decided to use hash with ID being the key, and value being the priority. Then in one SQL set I update it all at once. Now it is pretty fast. (defun hyperscope-hyperdocument-set-priority (hyperscope-set id direction) (let* ((hyperdocuments (rcd-sql-list (cond (hyperscope-set "SELECT hyobjects_id FROM hyobjects WHERE hyobjects_parent = $1 ORDER BY hyobjects_priorities, hyobjects_id") (t "SELECT hyobjects_id FROM hyobjects WHERE hyobjects_parent = NULL ORDER BY hyobjects_priorities, hyobjects_id")) cf-db hyperscope-set)) (hash (make-hash-table :test #'equal)) (renumbered (let ((count 20)) (mapcar (lambda (id) (puthash id (* (setq count (1+ count)) 10) hash)) hyperdocuments)))) (cond ((eq direction 'up) (puthash id (- (gethash id hash) 15) hash)) ((eq direction 'down) (puthash id (+ (gethash id hash) 15) hash)) (t (error "Verify arguments to `hyperscope-hyperdocument-set-priority'"))) (let* ((keys (hash-table-keys hash)) (sql (with-temp-buffer (insert "BEGIN;\n") (while keys (let ((key (pop keys))) (insert (format "UPDATE hyobjects set hyobjects_priorities = %s WHERE hyobjects_id = %s;\n" (gethash key hash) key)))) (insert "COMMIT;\n") (buffer-string)))) (rcd-sql sql cf-db)))) -- Jean Take action in Free Software Foundation campaigns: https://www.fsf.org/campaigns In support of Richard M. Stallman https://stallmansupport.org/