From: Adam Shelly <adam.shelly@...>
Date: 2008-04-25T05:54:55+09:00
Subject: Re: Pointer concept in Ruby ?

On 4/24/08, Iņaki Baz Castillo <ibc@aliax.net> wrote:
> Isn't there any mehotd more "normal"? something as:
>
> a2 = array[2]._something_
>
> a2="QWE"
>
> array[2]
> => "QWE"
>

There are probabaly a million reasons this is a bad idea, but what about:

 require 'ptrclass'
=> true
 a = [0,1,2,3]
=> [0, 1, 2, 3]
 ap = a.ptr(3)
=> 3
 ap.val=4
=> 4
 a
=> [0, 1, 2, 4]
 r=a.ptr(6)
=> nil
 r.val=4
=> 4
 a
=> [1, 34, 3, nil, nil, nil, 4]

--- ptrclass.rb----
class PtrClass < DelegateClass(Object)
  def initialize v
    super
    __setobj__ v
  end
  def val= v
    __setobj__ v
  end
end
class Array
  def ptr n
    v= self[n]
    self[n] =  v.is_a?(PtrClass) ? v : PtrClass.new(v)
  end
end

---
-Adam