From: Jon Leighton <j@...>
Date: 2011-12-14T18:48:23+09:00
Subject: [ruby-core:41645] [ruby-trunk - Bug #5761][Open] Array#flatten(N) calls to_ary on the (N+1)-level objects


Issue #5761 has been reported by Jon Leighton.

----------------------------------------
Bug #5761: Array#flatten(N) calls to_ary on the (N+1)-level objects
http://redmine.ruby-lang.org/issues/5761

Author: Jon Leighton
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]


$ cat flatten.rb
class Foo
  def respond_to?(name, include_private = true)
    puts "respond_to?(#{name})"
    super
  end

  def method_missing(name, *args)
    puts "method_missing(#{name})"
    super
  end
end

puts "[[Foo.new]].flatten(1)"
p [[Foo.new]].flatten(1)

puts
puts "[[[Foo.new]]].flatten(2)"
p [[[Foo.new]]].flatten(2)

puts
puts "[[[Foo.new]]].flatten(1)"
p [[[Foo.new]]].flatten(1)

$ ruby flatten.rb 
[[Foo.new]].flatten(1)
method_missing(to_ary)
respond_to?(to_ary)
[#<Foo:0x00000001ae41c8>]

[[[Foo.new]]].flatten(2)
method_missing(to_ary)
respond_to?(to_ary)
[#<Foo:0x00000001ae3d90>]

[[[Foo.new]]].flatten(1)
[[#<Foo:0x00000001ae3980>]]

$ ruby -v
ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]

Expected behaviour: no method calls are made on the (N+1)-level objects.

For what it's worth, this is the 1.8.7 output:

$ ruby flatten.rb 
[[Foo.new]].flatten(1)
respond_to?(to_ary)
[#<Foo:0x7fef3ebb1888>]

[[[Foo.new]]].flatten(2)
respond_to?(to_ary)
[#<Foo:0x7fef3ebb16a8>]

[[[Foo.new]]].flatten(1)
[[#<Foo:0x7fef3ebb14f0>]]


-- 
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