From: Brian Candler <B.Candler@...>
Date: 2003-05-08T15:54:56+09:00
Subject: Re: access a variables name?

On Thu, May 08, 2003 at 02:48:39PM +0900, Meinrad Recheis wrote:
> > a.instance_variable_get("@bar")  #>> 1
> > a.instance_variable_set("@baz",2)
> >
> but, what's that? i didn't find instance_variable_get/set in ruby's 
> documentation

It's a recent feature - it's not in 1.6.8 but it's in 1.8.0p2

You can query directly what methods are available in an object: e.g.

irb(main):005:0> class Foo; end
=> nil
irb(main):006:0> a=Foo.new
=> #<Foo:0x81b49dc>
irb(main):007:0> a.public_methods
=> ["untaint", "kind_of?", "type", "instance_variable_get", "inspect",
"frozen?", "taint", "send", "private_methods", "__id__", "method", "=~",
"to_a", "eql?", "dup", "hash", "singleton_methods", "display", "nil?",
"freeze", "is_a?", "class", "instance_variable_set", "methods", "__send__",
"instance_eval", "extend", "object_id", "instance_variables",
"instance_of?", "to_s", "copy_object", "id", "protected_methods", "equal?",
"respond_to?", "clone", "tainted?", "==", "public_methods", "==="]