From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.help Subject: Re: [External] : Supplying DOC string in a `defun' using `defvar' Date: Tue, 01 Jun 2021 01:31:30 +0200 Message-ID: <874keitr8t.fsf@web.de> References: Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="4759"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:YPks3CHNu4jyMV66mA81XBL/Md0= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Jun 01 01:32:03 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 1lnrO6-00014n-MO for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 01 Jun 2021 01:32:02 +0200 Original-Received: from localhost ([::1]:37326 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lnrO5-00023p-2V for geh-help-gnu-emacs@m.gmane-mx.org; Mon, 31 May 2021 19:32:01 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:36260) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lnrNj-00022S-Fi for help-gnu-emacs@gnu.org; Mon, 31 May 2021 19:31:39 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:37960) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lnrNi-0004Wv-2X for help-gnu-emacs@gnu.org; Mon, 31 May 2021 19:31:39 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1lnrNg-0000hB-M8 for help-gnu-emacs@gnu.org; Tue, 01 Jun 2021 01:31:36 +0200 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -13 X-Spam_score: -1.4 X-Spam_bar: - X-Spam_report: (-1.4 / 5.0 requ) BAYES_00=-1.9, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=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:130403 Archived-At: Drew Adams writes: > (let ((toto "WHAT?!!!!")) > (put 'bar 'function-documentation toto)) > > (describe-function 'bar) Yes, the `function-documentation` property. Its value can even be an expression, and that will be evaluated whenever the documentation is requested. In one of the simplest cases, that expression is a variable holding the documentation: #+begin_src emacs-lisp (defvar my-doc "A test function And this is its documentation") (defun test () 1) (put 'test 'function-documentation 'my-doc) ;; Try C-h f test RET #+end_src When you change the value of `my-doc' the documentation of `test' changes magically. There are cases in Emacs where the expression is used to generate a docstring dynamically - `pcase' is one example. Michael.