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: `apply-partially` and hash tables Date: Sun, 20 Oct 2024 16:29:10 -0400 Message-ID: References: <861q0b2jpo.fsf@fastmail.fm> <867ca27qfe.fsf@fastmail.fm> 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="29089"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:PKFilGKIv8nnRIqXPyJy43fqwMQ= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sun Oct 20 22:30:06 2024 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 1t2cYv-0007MK-JE for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 20 Oct 2024 22:30:05 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t2cYG-0003fn-9z; Sun, 20 Oct 2024 16:29:24 -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 1t2cYD-0003fX-Up for help-gnu-emacs@gnu.org; Sun, 20 Oct 2024 16:29:21 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t2cYC-0006RX-7R for help-gnu-emacs@gnu.org; Sun, 20 Oct 2024 16:29:21 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1t2cY9-0006ja-MK for help-gnu-emacs@gnu.org; Sun, 20 Oct 2024 22:29:17 +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: -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=0.17, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, 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-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:148197 Archived-At: Rudolf Schlatte [2024-10-20 21:12:33] wrote: > Stefan Monnier writes: >>> My question is the same, though: can it be relied upon? >> >> It's fundamental to the notion of what is a *value* (as in "call by >> value"), so yes, very much so. > > The usual caveat for lists applies: prepending values to the front or > otherwise mutating the list will not work as expected in general, since > what you're holding is just a cons cell. (This is an instance of the > "delete bug" where you have to write `(setq x (delete 'foo x))' instead > of just `(delete 'foo x)'.) AFAICT this behavior is a direct result of that same fundamental difference between a value and the thing it refers to, so not a caveat at all. Stefan