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=-3.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS shortcircuit=no autolearn=ham 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 7E11F1F454 for ; Thu, 7 Nov 2019 16:09:40 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 7EB3D120A29; Fri, 8 Nov 2019 01:09:30 +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 B4A7312095D for ; Fri, 8 Nov 2019 01:09:27 +0900 (JST) Received: by filter0078p3mdw1.sendgrid.net with SMTP id filter0078p3mdw1-29049-5DC441BD-33 2019-11-07 16:09:33.141119974 +0000 UTC m=+163410.713505082 Received: from herokuapp.com (unknown [34.230.5.86]) by ismtpd0010p1iad1.sendgrid.net (SG) with ESMTP id inu2yMiHQliw5CNHvm9Cqg for ; Thu, 07 Nov 2019 16:09:33.051 +0000 (UTC) Date: Thu, 07 Nov 2019 16:09:33 +0000 (UTC) From: daniel@dan42.com Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 71370 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 16295 X-Redmine-Issue-Author: byroot X-Redmine-Sender: Dan0042 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?8sy4RigFvRTdBfCVJrT9zb2J88PC92TMQwdNgaWYaq7CqjqwYInKvYR7aeFGnz?= =?us-ascii?Q?7DyKWqEEfwXoustfu3A=2Fx4G+4+eYpVDZZ0JZNM8?= =?us-ascii?Q?4rWg6A5HhhYbt1JfED9NiU9crt57qb85oWeIsYq?= =?us-ascii?Q?rxh2M9VxFdwaitSfhpobnQbPPJ7r9k9Tw5Yj8hM?= =?us-ascii?Q?XvdpCAVWRoVIyY5UYqXx1enQ2pd9DuZ=2FdtA=3D=3D?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 95745 Subject: [ruby-core:95745] [Ruby master Feature#16295] Chainable aliases for String#-@ and String#+@ 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 #16295 has been updated by Dan0042 (Daniel DeLorme). Description updated It would be nice to see some real-world examples where chaining of these methods makes sense. `"foo".-.size` (always 3) and ` ary.to_s.+.frozen?` (always false) are not very convincing. In my code I don't think I've ever wished to use these operations in the middle of a chain. ---------------------------------------- Feature #16295: Chainable aliases for String#-@ and String#+@ https://bugs.ruby-lang.org/issues/16295#change-82563 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- Original discussion https://bugs.ruby-lang.org/issues/16150?next_issue_id=16147&prev_issue_id=16153#note-40 In #16150, @headius raised the following concern about `String#-@` and `String#+@`: headius (Charles Nutter) wrote: > > Not exactly, -@ and +@ makes this much simpler > > I do like the unary operators, but they also have some precedence oddities: > > ``` > >> -"foo".size > => -3 > >> (-"foo").size > => 3 > ``` > > And it doesn't work at all if you're chaining method calls: > > ``` > >> +ary.to_s.frozen? > NoMethodError: undefined method `+@' for false:FalseClass > from (irb):8 > from /usr/bin/irb:11:in `
' > ``` > > But you are right, instead of the explicit `dup` with possible freeze you could use `-` or `+` on the result of `to_s`. However it's still not safe to modify it since it would modify the original string too. After working for quite a while with those, I have to say I agree. They very often force to use parentheses, which is annoying, and an indication that regular methods would be preferable to unary operators. In response @matz proposed to alias them as `String#+` and `String#-` without arguments: > How about making String#+ and #- without argument behave like #+@ and #-@ respectively, so that we can write: > > ``` > "foo".-.size > ary.to_s.+.frozen? > ``` My personal opinion is that descriptive method names would be preferable to `+/-`: > IMHO `.-` and `.+` is not very elegant. Proper method names explaining the intent would be preferable. > > - `-@` could be `dedup`, or `deduplicate`. > - `+@` could be `mutable` or `mut`. -- https://bugs.ruby-lang.org/