From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Emanuel Berg via Users list for the GNU Emacs text editor Newsgroups: gmane.emacs.help Subject: Re: avoid narrow-to-region (was: Re: replace-regexp) Date: Sun, 09 May 2021 08:59:57 +0200 Message-ID: <87bl9ktms2.fsf@zoho.eu> References: <87tunf1mz5.fsf@zoho.eu> <87v97v6mxg.fsf@gnu.org> <87wnsaz9df.fsf@zoho.eu> <877dkaytwu.fsf@zoho.eu> <87eeegx25w.fsf_-_@zoho.eu> <87fsywtp3f.fsf@zoho.eu> Reply-To: Emanuel Berg Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="30441"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:VoQ2Fz8fzEBF6vNrF4+Nw6WC/gA= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sun May 09 09:01:00 2021 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lfdQy-0007ka-Fb for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 09 May 2021 09:01:00 +0200 Original-Received: from localhost ([::1]:39410 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lfdQx-0006pu-J4 for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 09 May 2021 03:00:59 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:60110) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lfdQ7-0006pX-Bc for help-gnu-emacs@gnu.org; Sun, 09 May 2021 03:00:07 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:55864) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lfdQ5-00054H-SA for help-gnu-emacs@gnu.org; Sun, 09 May 2021 03:00:07 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1lfdQ3-0006m8-Te for help-gnu-emacs@gnu.org; Sun, 09 May 2021 09:00:03 +0200 X-Injected-Via-Gmane: http://gmane.org/ Mail-Followup-To: help-gnu-emacs@gnu.org Mail-Copies-To: never Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 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-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:129601 Archived-At: Yuri Khan wrote: >>> Consistency: If (f a b) returns t once, it must return >>> t when called again with the same arguments. [...] >> >> But here, we want to randomize _every time_. > > Every time you do a random shuffle, but not within > a single shuffle. Why not? > A theoretically sound (but still unnecessarily slow) > sorting-based shuffle would first assign a random weight to > each line, and then sort by that weight. > > But contrast with this: > > * Count the lines to be shuffled. Call it N. > * Generate a random number K_1 from 1 to N. Swap line 1 with line K_1. > * Generate a random number K_2 from 2 to N. Swap line 2 with line K_2. > ... > * Generate a random number K_{N-1} from N-1 to N. Swap line N-1 with > line K_{N-1}. DIY Yuri. > Almost easy enough to put in Elisp ... > and guarantees uniform distribution (as long as individual > random indexes are uniformly distributed). BTW, here is my other stuff, I'm pretty sure it all conforms to modern-day computer science theory of sorting, but I'll let you verify it just to be sure. https://dataswamp.org/~incal/emacs-init/sort-incal.el -- underground experts united https://dataswamp.org/~incal