From: Austin Ziegler <halostatue@...>
Date: 2005-10-26T03:28:34+09:00
Subject: Re: having reference problems

On 10/25/05, shalperin <shalperin@thebenefitbank.com> wrote:
> Here is a code snippet:
>
> class Foo
>   @a
>   @b
>   @reference

This is not necessary and definitely does not do what you want it to do.
It actually accesses the @a, @b, and @reference variables in the class
Foo.

>   def initialize()
>     @reference = [@a, @b]
>   end
>
>   attr_writer :a, :b, :reference
>   attr_reader :a, :b, :reference
> end
>
> f = Foo.new()
> f.reference[0] = 1
> puts f.a  #nil  WTF!
>
> What I am trying to do is refer to an instance variable both by its
> index in some array, and also directly.
>
> Any help would be greatly apreciated.

Hmmm. Won't work, because variables in Ruby are just labels, not
shoeboxes as they are in other programming languages. What problem are
you adctually trying to solve and we can help you find a Ruby way of
doing it.

  class Foo
    def initialize
      @reference = []
    end

    attr_accessor :a
    remove_method :a= ;
    def a=(_a)
      @reference[0] = @a = _a
    end

    attr_accessor :b
    remove_method :b= ;
    def b=(_b)
      @reference[1] = @b = _b
    end

    attr_reader   :reference
  end

That's closer to what you want, but it's very static and fragile. I
recommned looking closer at what you're trying to solve and finding
another solution.

-austin
--
Austin Ziegler * halostatue@gmail.com
               * Alternate: austin@halostatue.ca