From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Dmitry Gutov Newsgroups: gmane.emacs.devel Subject: Re: Any interest in a function like this to add to subr.el? Date: Tue, 18 Oct 2016 23:13:59 +0300 Message-ID: <68978e0f-03a3-70ec-c18a-e2d12f91ea5c@yandex.ru> References: NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1476821734 9241 195.159.176.226 (18 Oct 2016 20:15:34 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 18 Oct 2016 20:15:34 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:50.0) Gecko/20100101 Thunderbird/50.0 To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Oct 18 22:15:31 2016 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bwamt-000815-91 for ged-emacs-devel@m.gmane.org; Tue, 18 Oct 2016 22:15:03 +0200 Original-Received: from localhost ([::1]:43733 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bwamv-00054t-El for ged-emacs-devel@m.gmane.org; Tue, 18 Oct 2016 16:15:05 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:39977) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bwamA-0004ah-KX for emacs-devel@gnu.org; Tue, 18 Oct 2016 16:14:31 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bwalx-0000JI-6Q for emacs-devel@gnu.org; Tue, 18 Oct 2016 16:14:18 -0400 Original-Received: from mail-wm0-x22c.google.com ([2a00:1450:400c:c09::22c]:33485) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1bwalw-0000HP-Ni for emacs-devel@gnu.org; Tue, 18 Oct 2016 16:14:04 -0400 Original-Received: by mail-wm0-x22c.google.com with SMTP id g16so2073129wmg.0 for ; Tue, 18 Oct 2016 13:14:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:subject:to:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=RUOp3JfUOdNJCz4hCa+/eKW1jV3zhCrXqB855QiCdNE=; b=OUKEU2RGW3k5K3NXWA3MNbqigrPBLjpdmdeSc9tTO0R3Hkf8wZ0PL7K8Hy9yfCadKs HhWaXNYdxvnBgMAhhso+rEOro9HYay1AQspKb0PyXbrFM+lBQ+tYql9sAV4BYNGiHHaI V63CtcoehEhdrHVUdgqfsewZ9aELv8tiicf9mWql5QfRvhJxvjcW/CcNABYN++J3XMm2 qMGd6GKgN40WUrdev8QWvmj8oDagXMeHCdlo7U473nodDDhYKDPZuhQywjgbfpk2z+/C 9uWDk6O4g6sR5DsEVVxroKyJOI1Hs1luMY/e6OedbwdrncJ+OVMEt8FF+EnkS8MF1mHQ /eiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:subject:to:references:from:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=RUOp3JfUOdNJCz4hCa+/eKW1jV3zhCrXqB855QiCdNE=; b=BDESdNvQsyGIg4NeVXYXeaxiRUDwf0uVMu2qb91anO66B0yxcVewG0Q4sssPcPBFxB VTS7SVNOTvSGspULYyt+GtPWb0SOkTfnZpL47CmeI9NwXyLppwUGlG5VFXawXEq7+iId 0Tm0c1YQidJZbmwarbhZGwX3iN246AatbDvrM54BVBKOsX24KytpboCr9zFSY0atXA+N oZ2kfnJ6bPJDuH0HSp2E4Nb1iTCZsw8L7xNKoQT7Xz1CJaxDAC8vf8aqPc0+baaqSWW9 AT3cOzq2ooA5OMr9V6i6ia+QkVN37F4xHPe6Rz0Vo1TXifmdPMbSyt6i6R9a9TKYaxbt Fxrw== X-Gm-Message-State: AA6/9RkMxk3SDqItdfRQVdKgXwfg4oZ1cz9jbSwkCKQOE16YFRf8XXfS4XjerlMZHrwLSw== X-Received: by 10.28.131.212 with SMTP id f203mr12634548wmd.113.1476821643345; Tue, 18 Oct 2016 13:14:03 -0700 (PDT) Original-Received: from [192.168.1.3] ([185.105.173.41]) by smtp.googlemail.com with ESMTPSA id 137sm1180848wmu.2.2016.10.18.13.14.00 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Oct 2016 13:14:02 -0700 (PDT) In-Reply-To: Content-Language: en-US X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a00:1450:400c:c09::22c X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:208447 Archived-At: On 18.10.2016 20:53, John Wiegley wrote: > (defun sort-on (seq predicate accessor) > "Sort SEQ use PREDICATE applied to values returned by ACCESSOR. > This implements the so-called Schwartzian transform, which has > the performance advantage of applying ACCESSOR at most once per > element in the list, as opposed to using `sort' with a PREDICATE > that applies the ACCESSOR. > Note: this function is only a win over `sort' if ACCESSOR is > compute-intensive; otherwise, it uses more intermediate cons > cells than regular `sort', and so represents a memory for CPU > tradeoff." > (mapcar #'cdr (sort (mapcar #'(lambda (x) (cons (funcall accessor x) x)) seq) > #'(lambda (x y) (funcall predicate (car x) (car y)))))) Isn't this basically cl-sort, though?