From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: RFC: String interpolation Date: Mon, 12 Dec 2016 09:46:05 -0800 Organization: UCLA Computer Science Department Message-ID: <89a6a20d-e135-caad-6b31-760ab7ac90fc@cs.ucla.edu> References: <51825111-ace4-f750-4077-026a3b648d27@gmail.com> <8737hwnc52.fsf@lifelogs.com> <8c117f5c-209a-97d8-79ce-a78f707f0545@gmail.com> <76c9c475-0180-aa49-3d4a-006d4e3f943c@gmail.com> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1481564811 18041 195.159.176.226 (12 Dec 2016 17:46:51 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 12 Dec 2016 17:46:51 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 Cc: emacs-devel@gnu.org To: Lars Ingebrigtsen , Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Dec 12 18:46:48 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 1cGUgY-0003qQ-Rv for ged-emacs-devel@m.gmane.org; Mon, 12 Dec 2016 18:46:46 +0100 Original-Received: from localhost ([::1]:60117 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cGUgd-0003kF-54 for ged-emacs-devel@m.gmane.org; Mon, 12 Dec 2016 12:46:51 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:49959) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cGUg1-0003aj-9T for emacs-devel@gnu.org; Mon, 12 Dec 2016 12:46:14 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cGUfw-0006sU-AC for emacs-devel@gnu.org; Mon, 12 Dec 2016 12:46:13 -0500 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:49624) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cGUfw-0006sF-3M for emacs-devel@gnu.org; Mon, 12 Dec 2016 12:46:08 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id A6F321600C8; Mon, 12 Dec 2016 09:46:06 -0800 (PST) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 1SdiGw47qZdv; Mon, 12 Dec 2016 09:46:05 -0800 (PST) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id B7E2D160029; Mon, 12 Dec 2016 09:46:05 -0800 (PST) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id VcNJNDGGFOIB; Mon, 12 Dec 2016 09:46:05 -0800 (PST) Original-Received: from Penguin.CS.UCLA.EDU (Penguin.CS.UCLA.EDU [131.179.64.200]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 9E0C216021F; Mon, 12 Dec 2016 09:46:05 -0800 (PST) In-Reply-To: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 131.179.128.68 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:210356 Archived-At: Why not just extend "format" so that it allows trailing "...%" in the format string to mean "argument value spliced here"? After the argument you can continue on with the format, which must start with the rest of the conversion specification. E.g.: (format "Altitude= %" alt ".2f, direction = %" dir ".2f.") might output "Altitude = 300.57, direction = 240.93." That way, you can easily replace the expressions without giving them names: (format "Altitude= %" (+ alt 100) ".2f, direction = %" (- dir) ".2f.") This should provide the desired benefits without having to do anything fancy with variable scoping or changing the lexer or whatever.