From: "Brian Schröder" <ruby@...>
Date: 2004-12-11T04:59:10+09:00
Subject: How to make a deep copy of an object (Searching for Idiom)

Hello Group,

I sometimes which to make a deep copy of an object. I know I could use Marshal,
but thats slow so I want to write a routine #deep_copy. (Or should I overwrite
#dup ?)

Now the question is, how do you write those. I could use this:

class A
  ...
  def deep_copy
    result = self.dup
    result.field1 = self.field1.deep_copy
    ...
  end
end

or

class A
  def initialize(field1 = 'default value', ...)
    @field1 = field
    ...
  end

  def deep_copy
    self.new(@field1.deep_copy)
  end
end

Which allows me to use instance variables.

Is there something more elegant. What do you prefer? Am I on the right track?

Best regards,

Brian

-- 
Brian Schr�der
http://www.brian-schroeder.de/