From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eric Abrahamsen Newsgroups: gmane.emacs.help Subject: Quick pcase question Date: Wed, 02 Mar 2016 18:12:51 +0800 Message-ID: <87lh615gt8.fsf@ericabrahamsen.net> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1456913618 9917 80.91.229.3 (2 Mar 2016 10:13:38 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 2 Mar 2016 10:13:38 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Mar 02 11:13:28 2016 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ab3mX-0000EI-C3 for geh-help-gnu-emacs@m.gmane.org; Wed, 02 Mar 2016 11:13:25 +0100 Original-Received: from localhost ([::1]:55248 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ab3mW-0006ds-OC for geh-help-gnu-emacs@m.gmane.org; Wed, 02 Mar 2016 05:13:24 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:48951) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ab3mL-0006dE-5X for help-gnu-emacs@gnu.org; Wed, 02 Mar 2016 05:13:13 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ab3mH-0005EJ-Rm for help-gnu-emacs@gnu.org; Wed, 02 Mar 2016 05:13:13 -0500 Original-Received: from plane.gmane.org ([80.91.229.3]:33967) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ab3mH-0005Dy-Lp for help-gnu-emacs@gnu.org; Wed, 02 Mar 2016 05:13:09 -0500 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ab3mG-0008Sl-Bs for help-gnu-emacs@gnu.org; Wed, 02 Mar 2016 11:13:08 +0100 Original-Received: from 123.123.22.37 ([123.123.22.37]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 02 Mar 2016 11:13:03 +0100 Original-Received: from eric by 123.123.22.37 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 02 Mar 2016 11:13:03 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 21 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 123.123.22.37 User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) Cancel-Lock: sha1:H6jIdKvbUDSk++s0EIKOD3erLCo= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 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.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:109393 Archived-At: I'm enjoying pcase quite a bit, particular when employed as a kind of improved destructuring-bind. I think I've got the hang of most of it (despite the docs being a bit... succinct), but have one leftover question I keep running into. What I want to do is: "if this atom matches a predicate, the whole pattern matches, and also bind the atom to this local variable." Right now I'm making that work like this: (setq tst '(symbolla . "I'm the string")) (pcase tst (`(symbolla . ,(and x (pred stringp))) (message "cdr is a string: %s" x))) Is the ",(and x (pred stringp))" part really the simplest way of doing that? It just seems a little unintuitive. Thanks, Eric