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: [SOLVED with `eval']: Why I cannot use this variable in macro call from function? Date: Tue, 8 Jun 2021 22:27:04 +0300 Message-ID: References: <20210608183138.GA14693@tuxteam.de> 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="20428"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/2.0.7+183 (3d24855) (2021-05-28) Cc: Help GNU Emacs To: tomas@tuxteam.de Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Jun 08 21:32:15 2021 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 1lqhSR-00056W-1y for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 08 Jun 2021 21:32:15 +0200 Original-Received: from localhost ([::1]:49816 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lqhSQ-0001jE-4k for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 08 Jun 2021 15:32:14 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:42848) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lqhRY-0001Ad-Uk for help-gnu-emacs@gnu.org; Tue, 08 Jun 2021 15:31:23 -0400 Original-Received: from stw1.rcdrun.com ([217.170.207.13]:55713) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lqhRR-00080c-HD for help-gnu-emacs@gnu.org; Tue, 08 Jun 2021 15:31:19 -0400 Original-Received: from localhost ([::ffff:197.157.0.23]) (AUTH: PLAIN admin, TLS: TLS1.3,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 00000000000AE2EE.0000000060BFC57E.00000A59; Tue, 08 Jun 2021 12:31:10 -0700 Mail-Followup-To: tomas@tuxteam.de, Drew Adams , Help GNU Emacs Content-Disposition: inline In-Reply-To: <20210608183138.GA14693@tuxteam.de> Received-SPF: pass client-ip=217.170.207.13; envelope-from=bugs@gnu.support; helo=stw1.rcdrun.com X-Spam_score_int: -3 X-Spam_score: -0.4 X-Spam_bar: / X-Spam_report: (-0.4 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_SORBS_WEB=1.5, 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: 2.1.23 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:130641 Archived-At: Thanks Tomas. I know you have sharp mind. Is there a way to dynamically generate global variable based on a string and use it as history? It's interesting how this works: (defmacro rcd-gen-defvar (name description) `(defvar ,(intern name) nil ,description)) Now I can repeat and use the below and it will remember history: (read-from-minibuffer "Tell me: " nil nil nil (rcd-gen-defvar "my-history" "This is history")) I was expecting it NOT to work as I was expecting `defvar' to be repeated and to nullify the value, but it does not. In the next step all what I would need is to dynamically give "my-history" to macro `rcd-gen-defvar', but as I don't know how to do that, heaven thanks there is function `eval' which solves the problem. Now this function is to create the history variable if it does not exist and basically returns its symbol for completion function like the one below. (defun rcd-db-completing-table-history (table) (let ((rcd-symbol (intern (concat "rcd-db-completing-table-history-" table))) (description (format "History for table `%s'" table))) (if (boundp rcd-symbol) rcd-symbol (eval (list 'defvar rcd-symbol nil description))))) (defun rcd-db-combo-selection (table) (let* ((prompt (format "Select within table `%s': " table)) (prompt (append-colon-space prompt)) (sql (format "SELECT * FROM %s_combo ORDER BY id DESC" table))) (rcd-completing-read-sql-hash prompt sql cf-db (rcd-db-completing-table-history table)))) I have lost hours trying all possible combinations. From Lisp I do expect those combinations to be possible. At least `eval' works. It saves me continous variable definitions for each new foreign referenced table in PostgreSQL. I guess there must be few hundreds of such variables overall. Like table people_prefixes now receivs the variable `rcd-db-completing-table-history-prefixes' automatically for history. Table people_sufixes receives `rcd-db-completing-table-history-suffixes' automatically as that is useful to minimize repetitions and to avoid errors with the mixed input history. -- Jean Take action in Free Software Foundation campaigns: https://www.fsf.org/campaigns In support of Richard M. Stallman https://stallmansupport.org/