From: Benoit Daloze <eregontp@...>
Date: 2009-11-28T20:07:30+09:00
Subject: Re: Local variables can't be accessed from outside, right?

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class_local_a = class A
    def initialize
        @a = 11
        @@a = 22
        a = 33
    end
    @a = 1
    @@a = 2
    a = 3
end

p A.instance_variable_get(:@a) #ok

p A.class_variable_get(:@@a) if RUBY_VERSION > '1.9'
class A; p @@a end if RUBY_VERSION < '1.9'

# a little tricky, sure
p class_local_a

p A.new.instance_variable_get(:@a)

p A.class_variable_get(:@@a) if RUBY_VERSION > '1.9'
class A; p @@a end if RUBY_VERSION < '1.9'

p A.new.method(:initialize).call



I didn't find other way to get the result of class A ... end like a if or
case result.
Very weared a class' instance variable(1)
Does it have any interest?

2009/11/28 David Masover <ninja@slaphack.com>

> On Friday 27 November 2009 11:56:43 pm Michael Winterstein wrote:
> > Hi, I've been trying to figure out metaprogramming and I've mostly got
> > it figured out, but in doing so I ran across this example:
> >
> > class A
> >   def initialize
> >     @a = 11
> >     @@a = 22
> >     a = 33
> >   end
> >   @a = 1
> >   @@a = 2
> >   a = 3
> > end
> >
> >
> > This was given as a posed question (can you access all the variables)
> > and a particular order of the output was given (specifically, 1 2 3 11
> > 22 33).
>
> > I think a trick like puts A.new would be a lame solution,
>
> That actually wouldn't work, though I can see why you think it'd be lame.
>
> Anyway, as far as I know, there are only a few ways to access a local
> variable:
>
> You could define a= -- for example,
>
> def a=(value)
>  puts a
> end
>
> The problem is, I can't actually get this to work reliably. It really seems
> like assignment of this kind would only work if you did
>
> self.a = 33
>
> So, with that discarded, I don't think it's possible to get access to these
> local variables with the class as written, at least not cleanly. You could
> probably figure out (programatically) where the class is defined, and then
> parse the source.
>
> Other than that, the only way I know of getting at local variables is
> through
> the binding object, which you'd have to get either from inside the code, or
> from something called from that code -- but that class doesn't seem to call
> any methods from anywhere you care about, so that doesn't work.
>
>

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