From: Lars Westergren <lars.westergren@...>
Date: 2007-07-25T23:05:18+09:00
Subject: Re: Detecting singletons

Robert Dober skrev:
> On 7/25/07, Lars Westergren <lars.westergren@ki.se> wrote:
> well seems you have to use my code then, it depends on a "feature"
> Matz has put deliberately into the implementation of ancestor,
> singletons are not included.
> Does this fit your definition of singleton?

Not sure....    Your code works good in irb and catches singletons
created as
 class << self;self;end;

there. However, I still got the bug in Rails. I have done this-

marsh = class << Marshal; self; end
marsh.send :alias_method, "old_dump", "dump"
marsh.class_eval<<ENDOFSTRING
 def dump(o);
  STDERR.puts \"Problem class is a \" + o.class.name;
  STDERR.puts o.inspect;
  if o.class.is_singleton?;
    puts \"it's a singleton!\";
  else
     puts \"not a singleton...\";
  end;
  old_dump(o);
 end
ENDOFSTRING

And I get "not a singleton..." immediately followed by the exception.
The "problematic" object I think is the :session hash object, or rather
an object stored inside it. Either I'm looking in the wrong place, or I
need to traverse the object graph examening each object in array/hash.

Is there a library available for that?

I wish I could paste the inspect string for you people, but it is
several pages long and contains personal information.

Thanks again,
Lars