From: Gavin Sinclair <gsinclair@...>
Date: 2003-09-11T07:47:32+09:00
Subject: Re: What *are* variables? Which are nil now?

On Thursday, September 11, 2003, 4:00:10 AM, Hugh wrote:

> Reading about reflection, ObjectSpace will give you the objects in
> your system, possibly selected by Class.  Fine.  It won't tell you
> which variables are associated with them.  You can trace on global
> variables, you can look at instance variables, but how can you get
> information about all variables?  What *is* a variable, exactly, come
> to that?  It works like a sticky label so you can have two on the
> same object, but are the variables themselve objects in ruby?  Can I
> twist ObjectSpace's arm to tell me about them?

Variables are not objects; it's as simple as that.  They are sticky
notes.  You can get a list of local variables in any scope with
Kernel::local_variables.  Then you can eval them to find out what they
are.

You can get a list of variables in other scopes as well.  I have a
marvellous proof for this, which this margin is too small to contain.

Gavin