From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Marcin Borkowski Newsgroups: gmane.emacs.help Subject: Re: How does `describe-function' know where the source code of the function is? Date: Tue, 18 Jan 2022 18:41:25 +0100 Message-ID: <87ee55eybe.fsf@mbork.pl> References: <87pmorf1p5.fsf@mbork.pl> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="2815"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: mu4e 1.1.0; emacs 28.0.50 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 Tue Jan 18 18:42:56 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 1n9sVU-0000XD-0p for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 18 Jan 2022 18:42:56 +0100 Original-Received: from localhost ([::1]:57810 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n9sVT-0000r5-1e for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 18 Jan 2022 12:42:55 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:59060) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n9sUf-0000nY-0s for help-gnu-emacs@gnu.org; Tue, 18 Jan 2022 12:42:07 -0500 Original-Received: from mail.mojserwer.eu ([195.110.48.8]:42148) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n9sUY-0000W3-D0 for help-gnu-emacs@gnu.org; Tue, 18 Jan 2022 12:42:04 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id C8ACCE6838; Tue, 18 Jan 2022 18:41:33 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Original-Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NdauCX_-2YuW; Tue, 18 Jan 2022 18:41:29 +0100 (CET) Original-Received: from localhost (83.8.36.170.ipv4.supernova.orange.pl [83.8.36.170]) by mail.mojserwer.eu (Postfix) with ESMTPSA id 534C9E6177; Tue, 18 Jan 2022 18:41:29 +0100 (CET) In-reply-to: Received-SPF: pass client-ip=195.110.48.8; envelope-from=mbork@mbork.pl; helo=mail.mojserwer.eu 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, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.29 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:135430 Archived-At: On 2022-01-18, at 03:51, Stefan Monnier via Users list for the GNU Emacs text editor wrote: >> question is: how does `describe-function' know where the link should >> point to (and if it should be rendered at all)? I skimmed its source > > The name of the file is stored in `load-history`. The function > definition itself is then found (or not) by a naive regexp search. Thanks! This is actually kind of fascinating - on the one hand, it seems so fragile, and on the other hand, it works 99.99% of the time... Best, -- Marcin Borkowski http://mbork.pl