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: why are there [v e c t o r s] in Lisp? Date: Sat, 17 Oct 2015 17:09:38 +0200 Organization: Informatimago Message-ID: <87eggtcz0t.fsf@kuiper.lan.informatimago.com> References: <87oafzpqfj.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 1445094623 4047 80.91.229.3 (17 Oct 2015 15:10:23 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 17 Oct 2015 15:10:23 +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 Oct 17 17:10:20 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 1ZnT7k-0004xy-2F for geh-help-gnu-emacs@m.gmane.org; Sat, 17 Oct 2015 17:10:20 +0200 Original-Received: from localhost ([::1]:58604 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZnT7j-0000Pq-AD for geh-help-gnu-emacs@m.gmane.org; Sat, 17 Oct 2015 11:10:19 -0400 Original-Path: usenet.stanford.edu!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 33 Original-X-Trace: individual.net uc10wiDxTy1zjwrkU88Zawn7Wb9Vv0HMTKxZpL09AJMFILmDDs Cancel-Lock: sha1:M2VkYmRjYWQ4NTE2MmFlODU4NWRjY2E3MDAxOTdiMTNiM2VkYmIxMg== sha1:nBvJsHTeVx2nz7QDj13VR1kAi0I= 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:215422 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:107706 Archived-At: Emanuel Berg writes: > It seems to be like this: > > - in terms of linear algebra, a plain, finite list > with one and the same base data type as elements is > a vector as good as any > > - in terms of modeling, you can do all sorts of things > with this concept > > - in terms of Elisp programming, the vector type > shouldn't necessarily be thought of as a linear > algebra concept but rather another data structure > that can be used for many purposes, just like the > Elisp list, only most often specific purposes are > better suited for one or the other Yes. One could give a precise mathematical definition of computing objects. Usually, computing objects would have a complicated and trivial mathematical description, that wouldn't entirely correspond to the usual mathematical objects used, but some mapping is possible: this is how and why you can "represent" the usual mathematical objects with computing objects. If you want to see an example, of a precise mathematical definition of the computing object, have a look at the last chapter of r5rs. -- __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