From: "nobu (Nobuyoshi Nakada)" <nobu@...>
Date: 2012-06-26T12:42:30+09:00
Subject: [ruby-core:45876] [Backport93 - Backport #5124][Assigned] foo = [*bar] implies foo.equal?(bar)


Issue #5124 has been updated by nobu (Nobuyoshi Nakada).

Status changed from Feedback to Assigned
Assignee changed from ko1 (Koichi Sasada) to naruse (Yui NARUSE)


----------------------------------------
Backport #5124: foo = [*bar] implies foo.equal?(bar)
https://bugs.ruby-lang.org/issues/5124#change-27468

Author: adgar (Michael Edgar)
Status: Assigned
Priority: Normal
Assignee: naruse (Yui NARUSE)
Category: 
Target version: 


I just ran into this as a result of some slightly sloppy coding, but it did disagree with my internal assumptions.

Normally, I expect the Array literal syntax to create a new object, every time. So when I rewrote some code and ended up with something similar to the following, my tests broke, and I'm not sure that's how it should be. Here's the reduced test case:

some_ary = [1, 2, 3]
bar = [*some_ary]
bar << 4

p bar
>> [1, 2, 3, 4]
p some_ary
>> [1, 2, 3, 4]

I see it's clearly taking an opportunity for optimization, so I'm more than happy to hear that as a reason for rejecting this. It does warrant documentation somewhere, though, I'd say. Not sure where that documentation would go.


-- 
http://bugs.ruby-lang.org/