From: Simon Strandgaard <neoneye@...>
Date: 2004-03-14T21:59:35+09:00
Subject: Re: Object#clone and Object#dup

On Sat, 13 Mar 2004 14:44:54 +0100, Raphael Bauduin wrote:
> I'd like to duplicate n object, work on the copy, and be sure the original
> isn't change at all. How can I do that?
[snip]

Define your own #clone method, like this:

server> ruby a.rb 
#<A:0x810a760 @str="hellochanged!">
#<A:0x810a74c @str="hellochanged!">
server> ruby a.rb
#<A:0x810a60c @str="hellochanged!">
#<A:0x810a5d0 @str="hello">
server> expand -t2 a.rb 
class A
  def initialize(str)
    @str = str
  end
  attr_reader :str
  def change!
    @str << "changed!"
  end
  def clone
    A.new(@str.clone)
  end
end

a = A.new("hello")
b = a.clone
a.change!
p a, b
server>

--
Simon Strandgaard