From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS4713 221.184.0.0/13 X-Spam-Status: No, score=-2.6 required=3.0 tests=AWL,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY shortcircuit=no autolearn=no autolearn_force=no version=3.4.2 Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by dcvr.yhbt.net (Postfix) with ESMTP id 837211F934 for ; Fri, 2 Apr 2021 15:39:19 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 2C4B2120A21; Sat, 3 Apr 2021 00:38:15 +0900 (JST) Received: from xtrwkhkc.outbound-mail.sendgrid.net (xtrwkhkc.outbound-mail.sendgrid.net [167.89.16.28]) by neon.ruby-lang.org (Postfix) with ESMTPS id CA1B7120A20 for ; Sat, 3 Apr 2021 00:38:12 +0900 (JST) Received: by filterdrecv-p3mdw1-85cc49d4fc-m8v4h with SMTP id filterdrecv-p3mdw1-85cc49d4fc-m8v4h-19-60673A9D-56 2021-04-02 15:39:09.908227346 +0000 UTC m=+853566.277974726 Received: from herokuapp.com (unknown) by ismtpd0150p1iad2.sendgrid.net (SG) with ESMTP id pEKh3tULRau30C-rqpmI0A for ; Fri, 02 Apr 2021 15:39:09.807 +0000 (UTC) Date: Fri, 02 Apr 2021 15:39:09 +0000 (UTC) From: xtkoba+ruby@gmail.com Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 79231 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Feature X-Redmine-Issue-Id: 17773 X-Redmine-Issue-Author: sawa X-Redmine-Sender: xtkoba 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: =?us-ascii?Q?75w3+RXRrinEP3ykAS=2F1WzD2vTMrJdTeEiaFbXc9IwXcy7xerB3g1=2FUYOx1TxT?= =?us-ascii?Q?V1Q1rvjxfdFU+Camh4SsK6lk9JXneWoHTg=2Fo3b3?= =?us-ascii?Q?J1RNVqORDauljqahMRKxUOU93tWWDUhWO9+T7Q9?= =?us-ascii?Q?=2FjPRy3HamimEsyM+vYplmgFi1LyH7M2yY854Q72?= =?us-ascii?Q?qQgSbmQ8R7B5Cfm0OJW0NnlqcwfCjtbV1FQKXrK?= =?us-ascii?Q?+Rt5jx4m1HtOvcTV0=3D?= To: ruby-core@ruby-lang.org X-Entity-ID: b/2+PoftWZ6GuOu3b0IycA== X-ML-Name: ruby-core X-Mail-Count: 103188 Subject: [ruby-core:103188] [Ruby master Feature#17773] Alias `Numeric#zero?` and `Float#zero?` as `Numeric#empty?` and `Float#empty?` 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #17773 has been updated by xtkoba (Tee KOBAYASHI). An example of using `-1` as a default-ish integer value is to indicate "item not found" in a C-like language (see https://en.wikipedia.org/wiki/Sentinel_value). The following example seems to suggest that Ruby treats `0` as a default-ish integer value in some cases. ```ruby p nil.to_i # => 0 p "".to_i # => 0 ``` Yet I don't think that `0` should be treated as the special value in general, as long as we can freely assign both `nil` and an integer value to the same variable. ---------------------------------------- Feature #17773: Alias `Numeric#zero?` and `Float#zero?` as `Numeric#empty?` and `Float#empty?` https://bugs.ruby-lang.org/issues/17773#change-91263 * Author: sawa (Tsuyoshi Sawada) * Status: Open * Priority: Normal ---------------------------------------- When dealing with user input fields as in web applications, there are typical values that we want to consider as the default and/or absence of user input. For string/text inputs, list items, and attributes, we have `String#empty?`, `Array#empty?`, and `Hash#empty?` respectively, which seem to correspond to those cases. As for numerics, there are `Numeric#zero?` and `Float#zero?`. However, there is no single term that covers all these cases. In a routine to check through the fields whether there is user input, we have to selectively use `empty?` or `zero?` depending on the type of the input field. Many programming languages other than Ruby typically consider these values as falsy with respect to logical calculation. Ruby handles only `nil` and `false` as falsy, and that has clear advantages in many aspects, but with the cost of losing a simple way to handle these default values. I propose to alias `Numeric#zero?` as `Numeric#empty?` and `Float#zero?` as `Float#empty?` so that we can simply use `empty?`. At first, calling zero as empty might sound strange, but at least for non-negative integers, set theoretic definitions usually define zero as the empty set, so it is not that strange after all. Ruby on Rails' `blank?` is conceptually similar to this, but `0.blank?` returns `false`, so it is a different concept. -- https://bugs.ruby-lang.org/