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: if vs. when vs. and: style question Date: Fri, 27 Mar 2015 23:54:44 +0100 Organization: Informatimago Message-ID: <87d23uyrt7.fsf@kuiper.lan.informatimago.com> References: <87sicvwckx.fsf@wmi.amu.edu.pl> <87wq27yvqg.fsf@debian.uxu> <8d531e99-7260-4263-ac99-09c6871e2708@googlegroups.com> <87vbhq53lf.fsf@debian.uxu> <828c5115-a61b-4c42-b6d5-7bdcc6a691f0@googlegroups.com> <87bnjf8enq.fsf@debian.uxu> <877fu2t9l0.fsf@debian.uxu> 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 1427497532 8834 80.91.229.3 (27 Mar 2015 23:05:32 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 27 Mar 2015 23:05:32 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sat Mar 28 00:05:25 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 1YbdJX-0006LF-O2 for geh-help-gnu-emacs@m.gmane.org; Sat, 28 Mar 2015 00:05:19 +0100 Original-Received: from localhost ([::1]:52228 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YbdJW-00043p-NK for geh-help-gnu-emacs@m.gmane.org; Fri, 27 Mar 2015 19:05:18 -0400 Original-Path: usenet.stanford.edu!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 40 Original-X-Trace: individual.net UCB3bCzMi3k8PgSnsp9L8griSO6Tq5BmbFibMSIbm4aWvxkyvG Cancel-Lock: sha1:YjhkOGQ3YzdmYzkzYzZlYmZiZjIxOTIxY2ZiMzA1MGE5ZDMzM2ZmNg== sha1:a3kRHs1vsCIo8HUAlcAuxFDDEoU= 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:211127 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:103409 Archived-At: Emanuel Berg writes: > Hey... Why don't you Unicode and FP lovers do a new > editor called "Uhacs" (for Unicode, Haskell, and > Emacs) - the best thing with this editor is the > development time, which is actually zero. Because when > you start working on it, the result is a side-effect, > which is intolerable by definition, so you have to > stop :) Wait... oups, I did it again! But that joke > wasn't rude, was it? Rather, it is funny because it is > true :) Well, yes and no. That is, you can make the joke about purely functional systems running on Von Neuman archiectures, where anything is done only with side effects. But if you allow to consider the virtual machine provided by a purely function system, and ignore the internal side effects required to implement it, then you can indeed conceive a purely functionnal, side-effect-free editor. First of course, you have to start with a "side-effect-free" file system. So when you write a new file, you don't modify or erase the old file, you actually store the new file in free space, and build a new directory, almost similar to the old one, but with the new file in (and perhaps an "old" file out), and up to the root directory. You then have a new editor monad using this new root directory. Therefore it's not funny because it's false, you can write an editor without side effects at the level of your pure virtual machine and system. -- __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