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 "Bug reports for GNU Emacs, the Swiss army knife of text editors" Newsgroups: gmane.emacs.bugs Subject: bug#73886: 29.4; Confusing info about void function cells in Emacs Lisp manual Date: Sat, 19 Oct 2024 22:12:48 -0400 Message-ID: References: <86ldykj8a4.fsf@gnu.org> Reply-To: Stefan Monnier Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="21070"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: Ulrich =?UTF-8?Q?M=C3=BCller?= , 73886@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun Oct 20 04:14:02 2024 Return-path: Envelope-to: geb-bug-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 1t2LSE-0005N4-3x for geb-bug-gnu-emacs@m.gmane-mx.org; 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Sat, 19 Oct 2024 22:12:57 -0400 (EDT) In-Reply-To: <86ldykj8a4.fsf@gnu.org> (Eli Zaretskii's message of "Sat, 19 Oct 2024 20:45:55 +0300") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:293920 Archived-At: >> Section 13.9 "Accessing Function Cell Contents" of the GNU Emacs Lisp >> Reference Manual emphasizes the distinction between void and nil >> in function cells: >>=20 >> | Note that void is not the same as =E2=80=98nil=E2=80=99 or the symb= ol =E2=80=98void=E2=80=99. >> | The symbols =E2=80=98nil=E2=80=99 and =E2=80=98void=E2=80=99 are Lisp = objects, and can be stored into >> | a function cell just as any other object can be (and =E2=80=98void=E2= =80=99 can be a >> | valid function if you define it with =E2=80=98defun=E2=80=99). A void= function cell >> | contains no object whatsoever. Oops. Looks like I missed this part when I changed it back around Emacs-24.4: ** In 'symbol-function', nil and "unbound" are indistinguishable. 'symbol-function' does not signal a 'void-function' error any more. To determine if a symbol's function definition is void, use 'fboundp'. > I think the manual is wrong. Indeed. It was right for Emacs<24.4, tho. Stefan