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 75FC619C0031 for ; Thu, 5 Nov 2015 15:31:08 +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 F0F25B5D833 for ; Thu, 5 Nov 2015 16:00:03 +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 A4EE5952408 for ; Thu, 5 Nov 2015 16:00:03 +0900 (JST) Received: from [221.186.184.76] (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 6DEEF1204DC; Thu, 5 Nov 2015 16:00:01 +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 B981312047C for ; Thu, 5 Nov 2015 15:59:56 +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=AjO7/4TCWti4RMtIqD4kntr5p5g=; b=wFVe+6cl/a3tqQsF8Y eGm2iGjkDesQ1bsViWrMO82WYhgXuzQcvahvmu0ITaylVMcnXFBwcn1CzzLgw0iS Y39hZVEvd5tFPsAhZ4SIw1qDdeSVENFUYMghCm7s7wC15fQzLmmaFJsXD1q9e/LP CHcCzEcSvUsj2xU4vq411NjyY= Received: by filter-435.sjc1.sendgrid.net with SMTP id filter-435.9215.563AFE6925 2015-11-05 06:59:53.671144252 +0000 UTC Received: from herokuapp.com (ec2-54-242-132-215.compute-1.amazonaws.com [54.242.132.215]) by ismtpd0004p1iad1.sendgrid.net (SG) with ESMTP id oRf244CTSRSwflrHt_zEJQ for ; Thu, 05 Nov 2015 06:59:53.547 +0000 (UTC) Date: Thu, 05 Nov 2015 06:59:53 +0000 From: hanmac@gmx.de 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: 45989 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 11659 X-Redmine-Issue-Author: mwpastore X-Redmine-Sender: Hanmac 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/Ymy4QrNMhiuLXJG8OTL2vJD1yS5KGGT897lMvS5ZQXGH3U6d/zx+NthsE7k+Mp qEAovnrdEAEh/box+d0oz6Lkeg2ahUtvtLLn6eeA3EtybGDuiplIw0XYDI7qs6VqJ0bXpAmdn9YNMR eTRfk5qdZGSmvmw= X-ML-Name: ruby-core X-Mail-Count: 71349 Subject: [ruby-core:71349] [Ruby trunk - Bug #11659] Strange behavior setting previously-undefined local variables with a statement modifier 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 #11659 has been updated by Hans Mackowiak. ~~~ var2 = 'default' if defined?(var1).nil?; var2 ~~~ because you got a typo for var2, see the var1 inside. ~~~ var4 = 'default' if defined?(var4).nil?; var4 ~~~ the problem there is that var got defined from the parser before the code is run, so when it does check for defined, var4 is already defined also checkout: ~~~ var = "ok" if false; var #=> nil ~~~ ---------------------------------------- Bug #11659: Strange behavior setting previously-undefined local variables with a statement modifier https://bugs.ruby-lang.org/issues/11659#change-54717 * Author: Mike Pastore * Status: Open * Priority: Normal * Assignee: * ruby -v: ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-linux] * Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN ---------------------------------------- Consider a previously-undefined local variable `var1`: ~~~ irb(main):001:0> if defined?(var1).nil?; var1 = 'default'; end; var1 => "default" ~~~ Consider previously-undefined local variables `var1` and `var2`: ~~~ irb(main):001:0> var2 = 'default' if defined?(var1).nil?; var2 => "default" ~~~ Consider a previously-undefined local variable `var3`: ~~~ irb(main):001:0> var3 = 'default' if true; var3 => "default" ~~~ Consider a previously-undefined local variable `var4`: ~~~ irb(main):001:0> var4 = 'default' if defined?(var4).nil?; var4 => nil ~~~ Oops! Why is `var4` nil? Logically, considering the prior examples, it should be 'default'. Or are we missing something? http://stackoverflow.com/questions/33537059/unless-defined-is-not-working-in-my-code -- https://bugs.ruby-lang.org/