From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: poffice@blade.nagaokaut.ac.jp Delivered-To: poffice@blade.nagaokaut.ac.jp Received: from kankan.nagaokaut.ac.jp (kankan.nagaokaut.ac.jp [133.44.2.24]) by blade.nagaokaut.ac.jp (Postfix) with ESMTP id 5AC0719E0056 for ; Wed, 9 Dec 2015 14:51:59 +0900 (JST) Received: from voscc.nagaokaut.ac.jp (voscc.nagaokaut.ac.jp [133.44.1.100]) by kankan.nagaokaut.ac.jp (Postfix) with ESMTP id AC99DB5D8DA for ; Wed, 9 Dec 2015 15:23:41 +0900 (JST) Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by voscc.nagaokaut.ac.jp (Postfix) with ESMTP id 5602E18CC7B6 for ; Wed, 9 Dec 2015 15:23:41 +0900 (JST) Received: from [221.186.184.76] (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id C4B2F120566; Wed, 9 Dec 2015 15:23:39 +0900 (JST) X-Original-To: ruby-core@ruby-lang.org Delivered-To: ruby-core@ruby-lang.org Received: from o10.shared.sendgrid.net (o10.shared.sendgrid.net [173.193.132.135]) by neon.ruby-lang.org (Postfix) with ESMTPS id 6C5FC12045B for ; Wed, 9 Dec 2015 15:23:36 +0900 (JST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sendgrid.me; h=from:to:references:subject:mime-version:content-type:content-transfer-encoding:list-id; s=smtpapi; bh=eBQ3TxLaLowPOw78IhfrxSL4t3A=; b=ZfrMC81cOGKqZHE23r 7X2cjkn7Lhe/u89RAYQ0FtP7SQOZwVXG7MFcjAq6SJtc8GpnQLzvwvm+wWC2Zcdt ES/HmJhpIwxZeqdrjT/jw85wMhrXiv6wYruOjzXEeHT0Oy0ZS0L/pmpJzcc/WELB m281bBa5RpOTzDxozcAfGLdGw= Received: by filter0474p1mdw1.sendgrid.net with SMTP id filter0474p1mdw1.16733.5667C8E41A 2015-12-09 06:23:32.351843338 +0000 UTC Received: from herokuapp.com (ec2-54-196-144-109.compute-1.amazonaws.com [54.196.144.109]) by ismtpd0001p1iad1.sendgrid.net (SG) with ESMTP id GVL7qnG_RES3Urp_KxOicw for ; Wed, 09 Dec 2015 06:23:32.801 +0000 (UTC) Date: Wed, 09 Dec 2015 06:23:32 +0000 From: matthew@kerwin.net.au To: ruby-core@ruby-lang.org Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Redmine-MailingListIntegration-Message-Ids: 46687 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 11793 X-Redmine-Issue-Author: burnson X-Redmine-Sender: phluid61 X-Mailer: Redmine X-Redmine-Host: bugs.ruby-lang.org X-Redmine-Site: Ruby Issue Tracking System X-Auto-Response-Suppress: All Auto-Submitted: auto-generated X-SG-EID: ync6xU2WACa70kv/Ymy4QrNMhiuLXJG8OTL2vJD1yS7SQBKPYvV/EpPTpAHyIFNVodEb/DsmvBeWfC 1gEzbYIOORntnGWs/4C8d0aDYbOi+tkEiSYw9Cj2nzkko8VMsxs/IlDiksNLa8aryXysiGxb6l8hiJ Wc54q3sNS+PuO5cKuEvkiXouQI0zQW2pRc5PsTQ8KsW9jTnIHQ/chw3lLg== X-ML-Name: ruby-core X-Mail-Count: 71984 Subject: [ruby-core:71984] [Ruby trunk - Bug #11793] puts 'ab'.gsub('a', '\\+') - unexpected output X-BeenThere: ruby-core@ruby-lang.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: Ruby developers List-Id: Ruby developers List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #11793 has been updated by Matthew Kerwin. Substitution parameters work in string-string mode: ~~~ irb> puts 'ab'.gsub('a', %q(\`)) b irb> puts 'ab'.gsub('a', %q(\&)) ab irb> puts 'ab'.gsub('a', %q(\')) bb irb> puts 'ab'.gsub('a', %q(\0)) ab irb> puts 'ab'.gsub('a', %q(\\0)) ab irb> puts 'ab'.gsub('a', %q(\\\0)) \0b irb> puts 'ab'.gsub('a', %q(\\\+)) \+b ~~~ I used `%q()` to make it clear just how many blackslashes are involved. Note with the `\0` examples, either a single *or* double-backslash invokes the special value replacement. The plus symbol (`$+` or `\+`) is an alias for the `$LAST_PAREN_MATCH` special value, which in this case is blank. ---------------------------------------- Bug #11793: puts 'ab'.gsub('a', '\\+') - unexpected output https://bugs.ruby-lang.org/issues/11793#change-55393 * Author: William Burnson * Status: Rejected * Priority: Normal * Assignee: * ruby -v: ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-darwin15] * Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN ---------------------------------------- Test case: puts 'ab'.gsub('a', '\\\\+') Expected output: \\+b Actual output: b The way I understand gsub(pattern, replacement) when used with two string arguments is that it will perform a literal replacement, so it is quite unexpected that substituting with \\+ removes the pattern entirely. Doc: http://ruby-doc.org/core-2.2.3/String.html#method-i-gsub -- https://bugs.ruby-lang.org/