From: "headius (Charles Nutter)" <headius@...>
Date: 2012-11-27T01:44:22+09:00
Subject: [ruby-core:50170] [ruby-trunk - Bug #7437] Array#delete(obj) should return obj when there is an object that is equal in the array


Issue #7437 has been updated by headius (Charles Nutter).


marcandre (Marc-Andre Lafortune) wrote:
> Indeed, the documentation does not match the code and there is no test for this.
> 
> It was clearly Matz' intention to return the (last) deleted element: https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/18527
> 
> This is the most helpful behavior anyways.
> 
> I'll note that the documentation is clearly wrong in the second form too.
> 
> Unless there is objection, I'll commit the following patch:

Yes, it appears to have been an explicit behavioral change in the 1.9.1/1.8.7 timeframe that never got reflected in documentation.
----------------------------------------
Bug #7437: Array#delete(obj) should return obj when there is an object that is equal in the array
https://bugs.ruby-lang.org/issues/7437#change-33969

Author: hasari (Hiro Asari)
Status: Assigned
Priority: Normal
Assignee: marcandre (Marc-Andre Lafortune)
Category: core
Target version: 2.0.0
ruby -v: ruby 2.0.0dev (2012-11-25 trunk 37839) [x86_64-darwin12.2.1]


According to http://www.ruby-doc.org/core-1.9.3/Array.html#method-i-delete, Array#delete(obj) should return "obj" when there are objects in the array that are "equal to obj" (internally, "==" is used, it seems).

Notice that the documentation does not state that the return value is an element of the array itself. However, 1.9.3 and trunk both return a member of the Array, rather than the argument.

This issue was raised in https://github.com/jruby/jruby/issues/411

#!/usr/bin/env ruby

class Foo
  attr_reader :name, :age

  def initialize name, age
    @name = name
    @age = age
  end

  def == other
    other.name == name
  end
end

foo1 = Foo.new "John Shahid", 27
foo2 = Foo.new "John Shahid", 28
array = [foo1]
temp = array.delete foo2 # => foo1, not foo2


-- 
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