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: pcase bindings in patterns with complicated logic Date: Sun, 14 Jan 2024 15:42:50 +0000 Message-ID: <878r4rsyyt.fsf@localhost> References: <87il3xt38w.fsf@localhost> <875xzwjta2.fsf@posteo.net> 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="32019"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rms@gnu.org, emacs-devel@gnu.org To: Thierry Volpiatto Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Jan 14 16:40:33 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 1rP2bB-00088j-QE for ged-emacs-devel@m.gmane-mx.org; Sun, 14 Jan 2024 16:40:33 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rP2aP-0001XW-Ri; Sun, 14 Jan 2024 10:39:45 -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 1rP2aN-0001XA-VU for emacs-devel@gnu.org; Sun, 14 Jan 2024 10:39:44 -0500 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 1rP2aL-0002ro-Ha for emacs-devel@gnu.org; Sun, 14 Jan 2024 10:39:43 -0500 Original-Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 2184D240104 for ; Sun, 14 Jan 2024 16:39:38 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1705246779; bh=e7cidper3pxZ0X8Fe+1ENuijAlYAYY9BKbo8IJdmGIY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version: Content-Transfer-Encoding:From; b=lxUaTBDVoffq16hm+d4I/ONP3sZfxUlxvxrNCgKwmN7dqzwUW7JeDsGsMLqLX/6z6 TkQ94aycquXok3A6HZSzPbrzqO1gz8+NdZhab9PWdy3Z2/zxthmqe4AxEUc97giSv9 DnA/FUn0OcVlCVGTfsj1h8T57yagCDMmerYsMgcnM2HlnqUwA9x/RhrY58mNSEzNNK HAaMjoXZlvdnA+jTBjrd3x2gV74FC8izT49L5gCvBu9cGMUAKpsGVDBHecm8RwBACL RSNM9Y5FKPM8fqGJQz1CMrtLEJZQaGEHxH5bISq844W2ukSJoWCX+tD850EoLolVcx NRrheZbQube7A== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4TCfbG1VN3z6ty4; Sun, 14 Jan 2024 16:39:38 +0100 (CET) In-Reply-To: <875xzwjta2.fsf@posteo.net> Received-SPF: pass client-ip=185.67.36.66; envelope-from=yantar92@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_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:314964 Archived-At: Thierry Volpiatto writes: > [ BTW I don't understand why `app` pattern exists as long as now `pred` is > supporting an extra arg ] Isn't it explained right in the manual? =E2=80=98(app FUNCTION PATTERN)=E2=80=99 Matches if FUNCTION called on EXPVAL returns a value that matches PATTERN. FUNCTION can take one of the forms described for =E2=80=98pr= ed=E2=80=99, above. Unlike =E2=80=98pred=E2=80=99, however, =E2=80=98app=E2=80=99 = tests the result against PATTERN, rather than against a boolean truth value. > Also I would give a warning to extensions developers that want > compatibility with older emacs: > > pcase has evolved and doesn't behave as in older emacs, so try you pcase > statements on each emacs you want to support, for example (pred (not > ...)) is not supported in older Emacs. Compiler takes care about this warnings. For example, (pcase '(1) ((pred (not cdr)) "true")) in Emacs 26 will indicate problems Compiling file /tmp/test.el at Sun Jan 14 16:41:32 2024 test.el:2:15:Warning: reference to free variable =E2=80=98cdr=E2=80=99 --=20 Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at