From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: Generic functions: Specializers like `or' or `memq'? Date: Sat, 06 Nov 2021 19:29:02 -0400 Message-ID: References: <87cznfesji.fsf@ericabrahamsen.net> <87ilx6qo86.fsf@zoho.eu> Reply-To: Stefan Monnier Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="1217"; 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:xUFDKHA3Km5OPg0MD1400Wv+RTg= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sun Nov 07 00:29:38 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 1mjV7x-0000AU-Ll for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 07 Nov 2021 00:29:37 +0100 Original-Received: from localhost ([::1]:58228 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mjV7v-0000ms-UT for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 06 Nov 2021 19:29:35 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:44870) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mjV7X-0000mg-Fd for help-gnu-emacs@gnu.org; Sat, 06 Nov 2021 19:29:12 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:58200) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mjV7V-00007T-EB for help-gnu-emacs@gnu.org; Sat, 06 Nov 2021 19:29:11 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1mjV7T-000A7X-Od for help-gnu-emacs@gnu.org; Sun, 07 Nov 2021 00:29:07 +0100 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: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, 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: 2.1.29 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:134425 Archived-At: Emanuel Berg via Users list for the GNU Emacs text editor [2021-11-05 22:36:25] wrote: > Stefan Monnier via Users list for the GNU Emacs text editor wrote: >>> My earliest confusion began when I decided that if I could >>> find the part of the code that runs the `eql' specializer >>> (or do we call it the `eql' generalizer?) and then worked >>> back from there, I would be able to make sense of >>> everything. But I couldn't even find the bit of code that >>> looks like (eql )! And still can't. >> >> Nah, that would be too easy. Instead it happens implicitly >> via a lookup in a hash-table. >> >> I suspect that the code for cl-defstruct specializer might >> be easier to understand in this respect. > > What's the typical use case for this? Not sure what "this" refers to. If you're talking about the use case for adding new specializers/generalizers, it's quite rare. It's mostly a detail of `cl-generic.el` used internally. Stefan