From: Paul Brannan <pbrannan@...>
Date: 2005-05-18T05:36:37+09:00
Subject: Re: "Verbose" backtracing

If you are using a ruby later than 1.8 and you only need to know the
state of objects when an exception is raised, you could do something
like this:

  class Exception
    alias_method :old_init, :initialize
  
    attr_reader :state
  
    def initialize(*args)
      old_init(*args)
      @state = STATE_OBJS.map { |obj| obj.dup }
    end
  
    STATE_OBJS = []
  end
  
  def foo
    bar
  end
  
  def bar
    raise "testing!"
  end
  
  obj1 = [ 1, 2, 3 ]
  obj2 = "foo"
  Exception::STATE_OBJS << obj1
  Exception::STATE_OBJS << obj2
  
  begin
    foo()
  rescue => exc
    p exc.state #=> [[1, 2, 3], "foo"]
  end

Paul