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-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,UNPARSEABLE_RELAY 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 3979A1F4B4 for ; Tue, 30 Mar 2021 21:31:15 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 9C106120E3A; Wed, 31 Mar 2021 06:30:13 +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 01173120CA3 for ; Wed, 31 Mar 2021 06:30:06 +0900 (JST) Received: by filterdrecv-p3las1-699f5f7ff5-2h99c with SMTP id filterdrecv-p3las1-699f5f7ff5-2h99c-19-60639897-C1 2021-03-30 21:31:03.685738877 +0000 UTC m=+615474.793534894 Received: from herokuapp.com (unknown) by geopod-ismtpd-5-2 (SG) with ESMTP id Vm5WGm8xQX-_79o0KlweZw for ; Tue, 30 Mar 2021 21:31:03.439 +0000 (UTC) Date: Tue, 30 Mar 2021 21:31:03 +0000 (UTC) From: dan@danamis.com Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 79149 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Feature X-Redmine-Issue-Id: 16295 X-Redmine-Issue-Author: byroot X-Redmine-Sender: danh337 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?W222LJUvwIJXD0fuSPUfn3L88E5kwATu3GdlfyyAnYtTZ5YYAzTZb75rEt0cu9?= =?us-ascii?Q?3oRl1pSIzxex5nwEcLB2XAnbIhkoN2Aqq1aP568?= =?us-ascii?Q?TyPvtu4i+ygHWS1sntszioCSO=2F5uc0rXnm7bXcU?= =?us-ascii?Q?cxaJ+IWzR63hXKA7z8eYFSdn+rzUZ9YO7UC3LGG?= =?us-ascii?Q?8BE+anii4vOqy6leaK6g8b+zcf+8pP1P7aN4ySA?= =?us-ascii?Q?VV79GuIkqTGUaM3xs=3D?= To: ruby-core@ruby-lang.org X-Entity-ID: b/2+PoftWZ6GuOu3b0IycA== X-ML-Name: ruby-core X-Mail-Count: 103114 Subject: [ruby-core:103114] [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 danh337 (Dan Higgins). I believe this shows the semantics. It's the inverse of `.freeze`: `class String; def thaw; frozen? ? self.+@ : self; end; end` ---------------------------------------- Feature #16295: Chainable aliases for String#-@ and String#+@ https://bugs.ruby-lang.org/issues/16295#change-91180 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- 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/