From: Laza <lazax.com@...>
Date: 2005-12-01T09:57:31+09:00
Subject: Re: Point an element in Hash Object

Just a note about previous solution: referencing a reference does
daisy-chained lookups. So in the above example
  my_hash["file"].to_s
will send "to_s" my_hash["four"], which will then forward that message
to my_hash["one"].
So it would be more efficient (computationally) to reference directly,
and not indirectly. This is not the same as pointers in C/C++!

Also, recursive references will overflow the stack:

my_hash["six"] = "Sixth"
my_hash["six"] = Reference.new{my_hash["six"]}
SystemStackError: stack level too deep
        from (irb):40:in `method_missing'