From: Zev Blut <rubyzbibd@...>
Date: 2005-06-02T12:17:04+09:00
Subject: Re: binding, ObjectSpace._id2ref [WAS] Re: [ANN] parseargs-0.0.0

Hello,

On Thu, 02 Jun 2005 05:30:28 +0900, Ara.T.Howard <Ara.T.Howard@noaa.gov>  
wrote:

> the problem here is that the variables will only be __available__  
> through eval
> either.  eg. you'd have to
>
>    p 'eval a'
>
> and could never
>
>    p a
>
> i seem to recall a way of working around this but can't remember the  
> thread...
> if i can figure it out i'll add this feature.

Wow I am quite surprised at this!  It is quite odd that adding a
variable  through the use of eval, makes the variable appear in the
local_variables method, but that you cannot access the variable unless
you use eval... Below is a simpler example showing how using eval
modifies the the local_variables response.

----------------------------------------------------------------------
puts "[" + local_variables.join(" , ") + "]"
#=> []
eval 'a = 42'
puts "[" + local_variables.join(" , ") + "]"
#=> [a]
puts a
#=> undefined local variable or method `a' for main:Object (NameError)
----------------------------------------------------------------------

If you cannot access a in your binding, why would eval add a to the
local_variables?  Can anyone explain this?  I would like to know.

Thanks,
Zev Blut