From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ihor Radchenko Newsgroups: gmane.emacs.devel Subject: Re: Instead of pcase Date: Mon, 08 Jan 2024 15:42:00 +0000 Message-ID: <87o7dvygqf.fsf@localhost> References: <878r5inysw.fsf@localhost> <878r5ewk81.fsf@localhost> <87h6jxm8d4.fsf@localhost> <87a5pm762w.fsf@localhost> <874jfqwr2r.fsf@localhost> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="11362"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: rms@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Jan 08 16:39:36 2024 Return-path: Envelope-to: ged-emacs-devel@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 1rMrix-0002fS-Ei for ged-emacs-devel@m.gmane-mx.org; Mon, 08 Jan 2024 16:39:35 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rMriI-0007rF-AJ; Mon, 08 Jan 2024 10:38:54 -0500 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 1rMriG-0007qj-F5 for emacs-devel@gnu.org; Mon, 08 Jan 2024 10:38:52 -0500 Original-Received: from mout01.posteo.de ([185.67.36.65]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rMriE-0008Hk-1T for emacs-devel@gnu.org; Mon, 08 Jan 2024 10:38:52 -0500 Original-Received: from submission (posteo.de [185.67.36.169]) by mout01.posteo.de (Postfix) with ESMTPS id DA860240028 for ; Mon, 8 Jan 2024 16:38:47 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1704728327; bh=MTuhzkFrKEszbVo5VPYy+igEYhOnYUbvR5PEvbVR/9Y=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:From; b=Cqn83/KSYpUnra0W2G8Gy8k89ypJnYTNiJAI+ZoWfT944eKwIsWC+cniDydlzpN+I tucf9Zqzx+LDPx/YEc9JrEnOqW9m6i5sLllhX80BLhCIgfrrvS2LiW4XCZgbn3vVeo yIVb4GmzkO5wgGlBVOtg1J5JZbE+MmyeioQIIZDtxNAtNsr2Mw7wxBm+o9k+tRHYIs poJ2kmiUE3RJIX7Dql1caBLUMLYyLKAWlXHEaf7WcSg5Tt+vr1QeQjfNuvOhkAp/Rw mwEWLOIS5hLbVP2l9+1DsuC//kxUGDZ456lsOXf/gV9QKfw8VJ7y3lC3a2RtPqqs7k IKOpN7BLv4mnQ== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4T7ys32C2nz6tvs; Mon, 8 Jan 2024 16:38:47 +0100 (CET) In-Reply-To: Received-SPF: pass client-ip=185.67.36.65; envelope-from=yantar92@posteo.net; helo=mout01.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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:314751 Archived-At: Richard Stallman writes: > > > I wonder why people defined `xor'. It can't be used > > > as a conditional, like `and' and `or', so what is the point of it? > > > `xor' can be used as conditional > > Perhaps we are miscommunicating. > > `or' and `and' can act as conditionals. (and X Y) says to > do Y if X is true. (or X Y) says to do Y if X is false. > That is why those constructs are useful. IMHO, it is a better practice to do code flow control via special forms like `if', `when', `prog1', `progn', etc. In my mind, `or' and `and' are to be used as function (they are, indeed, functions). Treating them as flow control constructs may lead to confusion, as it did for you. > `xor' can'e be used as a conditional, because all of the arguments of > `xor' must always be evaluatedd. `xor' is a function - in cond*, PRED may be any function. And the fact that not all the arguments are evaluated in (PRED x arg1 arg2 ...) is the source of my confusion and the reason why I objected the idea of PRED in its current form when "x" not visually distinct from the rest of the arguments. -- Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at