From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Philip Kaludercic Newsgroups: gmane.emacs.help Subject: Re: (interactive) and &optional Date: Sat, 25 Mar 2023 13:12:48 +0000 Message-ID: <87fs9t3rfz.fsf@posteo.net> References: <25628.42021.832534.376361@woitok.gmail.com> <87jzz746ma.fsf@posteo.net> <25630.60070.913514.100455@woitok.gmail.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="20890"; mail-complaints-to="usenet@ciao.gmane.io" Cc: help-gnu-emacs@gnu.org To: Dr Rainer Woitok Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sat Mar 25 14:13:43 2023 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 1pg3iJ-0005Ar-3d for geh-help-gnu-emacs@m.gmane-mx.org; Sat, 25 Mar 2023 14:13:43 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pg3hb-0008ES-8p; Sat, 25 Mar 2023 09:12:59 -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 1pg3hZ-0008E0-Py for help-gnu-emacs@gnu.org; Sat, 25 Mar 2023 09:12:57 -0400 Original-Received: from mout02.posteo.de ([185.67.36.66]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pg3hX-0000gx-RR for help-gnu-emacs@gnu.org; Sat, 25 Mar 2023 09:12:57 -0400 Original-Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id A8FE6240130 for ; Sat, 25 Mar 2023 14:12:48 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1679749973; bh=jXaPFCHK8pRldO+22BRlz6flzE0H1rBwnxoYyAr3nH0=; h=From:To:Cc:Subject:Autocrypt:Date:From; b=rBFn7eA2auOL9mKOne9L4uEuaB0CagTrGIB1DGIrTBv37pyS4LEhE5TyH670hwoSo z9tvklBBrMR6docFNpVBW9Dxvm28cSqr6z97wN7ha90xrs4IH2ZJu42aV0L2WHXyVx kYcQE0I2kTx+MOwmDa29R8sM+AdEMW7swZIS20RgCTASQHDulwDwiSf+kgHAiE72lW ociq8lOyPAYTlW7+MHyWtGEaQc7vVY9dMODqxx3zTcrlVbtFtkgxXKsez2jmnUo4Yk DyM+bgobm/Bvneuxw2A7Dw10xJ7auxZJNndei0mAuBDs9wZbWI07IBq+VZxWR3btTX U2tSE0MNlxblQ== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4PkKJ038Z5z6tmL; Sat, 25 Mar 2023 14:12:48 +0100 (CET) In-Reply-To: <25630.60070.913514.100455@woitok.gmail.com> (Rainer Woitok's message of "Sat, 25 Mar 2023 13:35:51 +0100") Autocrypt: addr=philipk@posteo.net; keydata= mDMEZBBQQhYJKwYBBAHaRw8BAQdAHJuofBrfqFh12uQu0Yi7mrl525F28eTmwUDflFNmdui0QlBo aWxpcCBLYWx1ZGVyY2ljIChnZW5lcmF0ZWQgYnkgYXV0b2NyeXB0LmVsKSA8cGhpbGlwa0Bwb3N0 ZW8ubmV0PoiWBBMWCAA+FiEEDg7HY17ghYlni8XN8xYDWXahwukFAmQQUEICGwMFCQHhM4AFCwkI BwIGFQoJCAsCBBYCAwECHgECF4AACgkQ8xYDWXahwulikAEA77hloUiSrXgFkUVJhlKBpLCHUjA0 mWZ9j9w5d08+jVwBAK6c4iGP7j+/PhbkxaEKa4V3MzIl7zJkcNNjHCXmvFcEuDgEZBBQQhIKKwYB BAGXVQEFAQEHQI5NLiLRjZy3OfSt1dhCmFyn+fN/QKELUYQetiaoe+MMAwEIB4h+BBgWCAAmFiEE Dg7HY17ghYlni8XN8xYDWXahwukFAmQQUEICGwwFCQHhM4AACgkQ8xYDWXahwukm+wEA8cml4JpK NeAu65rg+auKrPOP6TP/4YWRCTIvuYDm0joBALw98AMz7/qMHvSCeU/hw9PL6u6R2EScxtpKnWof z4oM Received-SPF: pass client-ip=185.67.36.66; envelope-from=philipk@posteo.net; helo=mout02.posteo.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=-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-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:143109 Archived-At: Dr Rainer Woitok writes: > Philip, > > On Thursday, 2023-03-23 19:20:29 +0000, you wrote: > >> ... >> > as expected, while calling "M-x fun" and then just typing "RET" at the >> > prompt returns >> > >> > val:.\n >> > >> > that is, an empty symbol or string. >> >> Right. > > That's a bit flabbergasting: experimenting some more with my function, I > found that "symbolp" really returns t in case of empty responses, mean- > ing there really is such a thing as an empty symbol. So how can I test > for an empty symbol? I am guessing it is not an "empty symbol" (to my knowledge the term is not defined), but rather the fact that `nil' is a symbol. Depending on what you did, it might also be that you are interning the empty string, which creates a symbol with an empty string as the symbol name -- which is not unique. > There doesn't seem to be a function "symbol-empty- > p" while, strictly speaking, "string-empty-p" shouldn't be applyable to > symbols at all, should it? No, trivially because a symbols is not a string, and shouldn't be regarded as similar data types. Depending on the context, it might be totally justified to regard the symbol name of a symbol as totally incidental. > Does an empty symbol have an external repre- > sentation like an empty list or string, allowing the use of "eq"? A symbol is eq to all other symbols that were either created by passing the same (equal) string to `intern' or by the same invocation of `make-symbol'. That could be useful if you are trying to handle a symbol that as an empty string as the symbol name -- but at that point I think it would be better to just check the string before it is interned. > Sincerely, > Rainer -- Philip Kaludercic