From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Sebastian Tennant Newsgroups: gmane.emacs.help Subject: Re: A macro and an unwanted containing list in the resulting form Date: Thu, 24 May 2007 00:45:54 +0300 Message-ID: <87d50r8b8t.fsf@moley.org> References: <873b1nye2g.fsf@moley.org> <87abvvv5ob.fsf@thalassa.lan.informatimago.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1179959892 12966 80.91.229.12 (23 May 2007 22:38:12 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Wed, 23 May 2007 22:38:12 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu May 24 00:38:04 2007 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1HqzT1-0006XU-OG for geh-help-gnu-emacs@m.gmane.org; Thu, 24 May 2007 00:38:04 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HqzT3-0004xk-Ns for geh-help-gnu-emacs@m.gmane.org; Wed, 23 May 2007 18:38:05 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1HqzSr-0004xc-7h for help-gnu-emacs@gnu.org; Wed, 23 May 2007 18:37:53 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1HqzSp-0004xQ-4u for help-gnu-emacs@gnu.org; Wed, 23 May 2007 18:37:51 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HqzSp-0004xN-1H for help-gnu-emacs@gnu.org; Wed, 23 May 2007 18:37:51 -0400 Original-Received: from main.gmane.org ([80.91.229.2] helo=ciao.gmane.org) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1HqzSo-00036z-Gr for help-gnu-emacs@gnu.org; Wed, 23 May 2007 18:37:50 -0400 Original-Received: from list by ciao.gmane.org with local (Exim 4.43) id 1Hqz3x-0001VM-IF for help-gnu-emacs@gnu.org; Thu, 24 May 2007 00:12:10 +0200 Original-Received: from 85.105.17.65 ([85.105.17.65]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 24 May 2007 00:12:09 +0200 Original-Received: from sebyte by 85.105.17.65 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 24 May 2007 00:12:09 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 39 Original-X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: 85.105.17.65 User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.0.95 (gnu/linux) Cancel-Lock: sha1:+ujb2ltqJI/k6fxQYZJJBSNcod8= X-detected-kernel: Linux 2.6, seldom 2.4 (older, 4) X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:44352 Archived-At: Quoth Pascal Bourguignon : > Sebastian Tennant writes: >>> Is there any reason to make the argument of build-cond an alist? You >>>could try >>> >>> (defmacro build-cond (&rest conds) >>> (append '(cond) >>> (mapcar '(lambda (each) >>> (cons (list 'equal 'my-var (car each)) (list (cdr each)))) >>> conds))) >>> >>> and then use >>> >>> (build-cond ("hello" . (message "hi")) >>> ("goodbye" . (message "bye")) >> >> The reason for the alist is the clauses are being passed as one of a >> number of arguments to a function call. > > If you get the a-list as argument to a function, then you don't need a > macro to process it! Just write a loop! > > (require 'cl) > > (defun my-function (string clauses) > (loop > for clause in clauses > until (string= string (car clause)) > finally (eval (cdr clause)))) > > (my-function "goodbye" '(("hello" . (message "hi")) > ("goodbye" . (message "bye")))) > Whoa! This isn't LISP! At least it doesn't look like it to me. Where are the parentheses? I suppose I haven't got the first idea how the Common Lisp 'loop' function works...??? Sebastian