How to create an operator for deep copy/cloning of objects in Ruby?

Question

I would like to achieve the following by introducing a new operator (e.g. :=)

a := b = {}
b[1] = 2
p a # => {}
p b # => {1=>2}
<         


        

Answer 1

First of all, the syntax for superators is

superator ":=" do |operand|
  #code
end

It's a block, because superator is a metaprogramming macro.

Secondly, you have something going their with Marshal...but it's a bit of magic-ish. Feel free to use it as long as you understand exactly what it is you're doing.

Thirdly, what you are doing isn't quite doable with a superator (I believe), because self cannot be modified during a function. (if someone knows otherwise, please let me know)

Also, in your example, a must first exist and be defined before being able to call the method := in it.

Your best bet is probably:

class Object
  def deep_clone
    Marshal::load(Marshal.dump(self))
  end
end

to generate a deep clone of an object.

a = (b = {}).deep_clone
b[1] = 2
p a # => {}
p b # => {1=>2}