From: Tony Arcieri <tony.arcieri@...>
Date: 2010-10-31T04:49:20+09:00
Subject: Re: Dynamically reference instance vars

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On Sat, Oct 30, 2010 at 1:27 PM, Greg Willits <lists@gregwillits.ws> wrote:

> The question is whether there's a shorter way to do this:
>
>  my_object.send(:instance_variable_set, "@#{iname}", ivalue)
>
> In another language I used, I could simply do the equivalent of
>
>  myobject.iname = ivalue
>

This breaks the encapsulation that objects are supposed to provide for their
hidden state. I have to say I *like* the fact that
instance_variable_get/instance_variable_set are long and unwieldy. By using
them  you hopefully remind yourself that you're doing something naughty by
touching an object's private parts.


> I was hoping in Ruby that at least this was possible:
>
>  myobject.send(iname) = ivalue
>  --or--
>  myobject.send(iname, ivalue)
>
> but that doesn't work. I could maybe force it to work by manually
> creating setter methods, but that's not an elegant solution either, I'd
> rather have the occassional use of instance_variable_set than craft
> setters.


It's Ruby, a lot is possible! You could add some method_missing magic so:

  myobj.iv_foobar = 42

thunks to:

  instance_variable_set(:@foobar, 42)

I would strongly recommend against that sort of thing though.

-- 
Tony Arcieri
Medioh! A Kudelski Brand

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