From: Paul Brannan <pbrannan@...>
Date: 2002-09-10T22:43:01+09:00
Subject: Re: ruby-dev summary 18111-18212

On Tue, Sep 10, 2002 at 09:17:39AM +0900, Yukihiro Matsumoto wrote:
> Hi,
> 
> In message "Re: ruby-dev summary 18111-18212"
>     on 02/09/09, Paul Brannan <pbrannan@atdesk.com> writes:
> 
> |Someone on irc pointed out that there is an Object#become in CVS now.
> |When I look at the source, though, it doesn't look like it does anything
> |except raise an exception if obj is frozen or if obj and orig are not
> |the same type.  Then it returns the original object.
> 
> Because "become" is a method to copy internal state that Ruby
> interpreter does not know, the default "become" does nothing but
> freeze check.

Interesting.  Is this what "become" does in Smalltalk?

Also, in Ruby 1.6 I might write:

  class Foo
    def clone
      puts "clone!"
      return Foo.new
    end
  end
  
  f = Foo.new
  p f.dup

I'm implementing only "clone" because dup in 1.6 is implemented in
terms of clone.  So the output I get from 1.6 is:

  clone!
  #<Foo:0x402929dc>

but Ruby 1.7 gives me:

  #<Foo:0x401da550>

if I want to implement dup/clone for an object in an extension, what is
the correct way to do this so that it will work with both 1.6 and 1.7?

Paul