From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: Re: why are there [v e c t o r s] in Lisp? Date: Sat, 17 Oct 2015 23:06:32 +0200 Message-ID: <87k2qlw6g7.fsf@debian.uxu> References: <87mvvjeg29.fsf@kuiper.lan.informatimago.com> <87eggvebfs.fsf@kuiper.lan.informatimago.com> <87pp0eckss.fsf@kuiper.lan.informatimago.com> <87a8rhcypj.fsf@kuiper.lan.informatimago.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1445115482 10954 80.91.229.3 (17 Oct 2015 20:58:02 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 17 Oct 2015 20:58:02 +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 22:57:53 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 1ZnYY4-0007Ve-7U for geh-help-gnu-emacs@m.gmane.org; Sat, 17 Oct 2015 22:57:52 +0200 Original-Received: from localhost ([::1]:59729 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZnYY3-0000SO-EZ for geh-help-gnu-emacs@m.gmane.org; Sat, 17 Oct 2015 16:57:51 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:37320) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZnYXt-0000SJ-CI for help-gnu-emacs@gnu.org; Sat, 17 Oct 2015 16:57:42 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZnYXp-0002El-CC for help-gnu-emacs@gnu.org; Sat, 17 Oct 2015 16:57:41 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:43893) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZnYXp-0002Ec-55 for help-gnu-emacs@gnu.org; Sat, 17 Oct 2015 16:57:37 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZnYXk-0007Dn-F6 for help-gnu-emacs@gnu.org; Sat, 17 Oct 2015 22:57:32 +0200 Original-Received: from nl106-137-244.student.uu.se ([130.243.137.244]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 17 Oct 2015 22:57:32 +0200 Original-Received: from embe8573 by nl106-137-244.student.uu.se with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 17 Oct 2015 22:57:32 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Original-Lines: 43 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: nl106-137-244.student.uu.se Mail-Copies-To: never User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) Cancel-Lock: sha1:kW8SaXfUHPpwi0XRYhO9ha9Pkco= 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:107722 Archived-At: "Pascal J. Bourguignon" writes: > You are asking why apples are of a certain color, > even as peaches have a kernel. OK - why is that? > I don't know what you mean by "this" in "figure this > out on its own". As I know you know, there are languages (e.g., SML) that do have types but still it isn't compulsory to spell them out in the code. The types are instead inferred, "leaving the programmer free to omit type annotations while still permitting type checking." [1] > The speed is irrelevant here, there are semantic > differences: > > (setf print-circle t) (loop repeat 3 collect [1 2 3]) > --> (#1=[1 2 3] #1# #1#) (loop repeat 3 collect > (vector 1 2 3)) --> ([1 2 3] [1 2 3] [1 2 3]) It is since several posts clear that lists and vectors are two different general-purpose data structures, with different properties with respect to access times and memory allocation policy, and also with different methods to interact with the data - because they are different types. In particular, the vector is a 1-dimensional array, and not an implementation/tool to specifically do linear algebra or any other math or science discipline that uses vectors as the modeling building blocks. This is not to say that cannot happen, just as it can happen with lists being the base data structure. [1] https://en.wikipedia.org/wiki/Type_inference -- underground experts united http://user.it.uu.se/~embe8573