From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Pascal J. Bourguignon" Newsgroups: gmane.emacs.help Subject: Re: elisp newbie: simplifying from cl structures? Date: Sun, 08 Feb 2015 04:37:38 +0100 Organization: Informatimago Message-ID: <87iofdnke5.fsf@kuiper.lan.informatimago.com> References: <87mw4pnsr6.fsf@kuiper.lan.informatimago.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: ger.gmane.org 1423367125 2287 80.91.229.3 (8 Feb 2015 03:45:25 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 8 Feb 2015 03:45:25 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sun Feb 08 04:45:24 2015 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 1YKIoE-0000s1-5A for geh-help-gnu-emacs@m.gmane.org; Sun, 08 Feb 2015 04:45:22 +0100 Original-Received: from localhost ([::1]:55450 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YKIoD-0007en-4p for geh-help-gnu-emacs@m.gmane.org; Sat, 07 Feb 2015 22:45:21 -0500 Original-Path: usenet.stanford.edu!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 56 Original-X-Trace: individual.net KtTeHga19BGePFBuTpkvFwoST5rLJtUDBVdyd50w6h2TayFvqT Cancel-Lock: sha1:N2M2OGFmNWUyMWZhMjk1NmE5NDdlNTM1MGQzYThjNWVlZjM3NzM3Yw== sha1:bUBOAhdq/pw+zzAqos0w/BaLYoY= Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwAQMAAABtzGvEAAAABlBMVEUAAAD///+l2Z/dAAAA oElEQVR4nK3OsRHCMAwF0O8YQufUNIQRGIAja9CxSA55AxZgFO4coMgYrEDDQZWPIlNAjwq9 033pbOBPtbXuB6PKNBn5gZkhGa86Z4x2wE67O+06WxGD/HCOGR0deY3f9Ijwwt7rNGNf6Oac l/GuZTF1wFGKiYYHKSFAkjIo1b6sCYS1sVmFhhhahKQssRjRT90ITWUk6vvK3RsPGs+M1RuR mV+hO/VvFAAAAABJRU5ErkJggg== X-Accept-Language: fr, es, en User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) Original-Xref: usenet.stanford.edu gnu.emacs.help:210299 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:102575 Archived-At: torys.anderson@gmail.com (Tory S. Anderson) writes: > Thanks for helping me straighten the code out and gain better > understanding cl-tools and structure; it loads and mostly > works. Thanks! > > (defun change-smtp () > "Change the SMTP server according to the current from line." > (save-excursion > (cl-loop with from = (save-restriction > (message-narrow-to-headers) > (message-fetch-field "from")) > for (address server port) in smtp-accounts > do (if (string-match address from) > (return (funcall 'set-smtp server port address)) > (message "Failed to match %s with %s" address from)) > finally (error "Cannot infer SMTP information.")))) > > (add-hook 'message-send-mail-hook 'change-smtp) Ok, but now, you should consider that this functions is performing several tasks of different order: some parsing of a message is done, as well as some searching for smtp configuration, and some setting of smtp configuration. That's a lot for a single function. It would be better if you split it as follow, which would give you two nice reusable functions, and makes change-smtp clearer: (defun message-from-field () "Find the from field in the current buffer that must contain a message." (save-excursion (save-restriction (message-narrow-to-headers) (message-fetch-field "from")))) (defun find-smtp-account (address accounts) "Find the first account in `accounts' whose address matches `address'." (find from accounts :key (function first) :test (lambda (from address) (string-match address from)))) (defun change-smtp () (let ((from (message-from-field))) (destructuring-bind (address server port) (find-smtp-account from smtp-accounts) (if address (funcall 'set-smtp server port address) (error "Cannot not infer SMTP information"))))) -- __Pascal Bourguignon__ http://www.informatimago.com/ “The factory of the future will have only two employees, a man and a dog. The man will be there to feed the dog. The dog will be there to keep the man from touching the equipment.” -- Carl Bass CEO Autodesk