From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: What does "lacks a prefix" mean? Date: Fri, 10 Jul 2015 13:04:30 -0400 Message-ID: References: <1e0ad02f-ca3e-495c-bb85-61f77090d31d@googlegroups.com> <87bnfmqzn2.fsf@kuiper.lan.informatimago.com> <87io9ui67a.fsf@nl106-137-147.student.uu.se> <871tghj720.fsf@nl106-137-147.student.uu.se> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1436547918 22697 80.91.229.3 (10 Jul 2015 17:05:18 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 10 Jul 2015 17:05:18 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Jul 10 19:05:10 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 1ZDbjV-0003rJ-Kx for geh-help-gnu-emacs@m.gmane.org; Fri, 10 Jul 2015 19:05:05 +0200 Original-Received: from localhost ([::1]:45501 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZDbjU-0003Zd-T7 for geh-help-gnu-emacs@m.gmane.org; Fri, 10 Jul 2015 13:05:04 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35302) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZDbjF-0003ZM-1B for help-gnu-emacs@gnu.org; Fri, 10 Jul 2015 13:04:49 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZDbjB-0001U2-S2 for help-gnu-emacs@gnu.org; Fri, 10 Jul 2015 13:04:48 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:41816) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZDbjB-0001Tp-Lj for help-gnu-emacs@gnu.org; Fri, 10 Jul 2015 13:04:45 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZDbj9-0003eJ-Fc for help-gnu-emacs@gnu.org; Fri, 10 Jul 2015 19:04:43 +0200 Original-Received: from 157-52-6-103.cpe.teksavvy.com ([157.52.6.103]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 10 Jul 2015 19:04:43 +0200 Original-Received: from monnier by 157-52-6-103.cpe.teksavvy.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 10 Jul 2015 19:04:43 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 21 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 157-52-6-103.cpe.teksavvy.com User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) Cancel-Lock: sha1:u7/m+zwQtIWvftlilYub07fdJDc= 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:105585 Archived-At: >> let* says "I need variables which depend on each >> other" and if they're really not, that look strange. If let behaved like let* it wouldn't look strange to you. Many other functional languages dropped the "simultaneous let" and only kept the equivalent of let* (or even letrec). >> And probably it's a bit slower. Regarding efficiency, there's no clear winner between the two. It's basically irrelevant. >> And non-parallelizable theoretically :) In practice neither is easily parallelizable anyway. And the work needed to auto-convert a "let*" to a "let" when possible is trivial in comparison to what's needed to parallelize the code. So again, it's really irrelevant. Stefan