From: Tom Sawyer <transami@...>
Date: 2003-01-04T14:16:09+09:00
Subject: Cyclic Marshals :: again the need for a built in creation parent method

okay, after way too many hours i was finally able to Marshal my objects and 
overcome the cyclic references that caused a spiraling depth problem. 
unfortunately it is not a general purpose solution. i could not figure a way 
to do that. rather i created two methods, a #pre_dump methods that nil'd out 
the specific cyclic references in my objects before the #Marshal.dump and a 
#post_load method that restores them after the #Marshal.load.

thes whole of this problem stems from the common need to store the creation 
parent of an object:

	class ParentObject
		def method_x
			c = ChildObject.new(self)
		end
	end

	def ChildObject
		def initialize(parent)
			@parent = parent
		end
	end

i have talked about this before. this is fairly common occurance. i have heard 
it argued that it is better to have it explicitly defined like this, but 
among many other things, Marshalling is another example in which having a 
built in method (#creator perhaps) akin to #self would be of great use simply 
because the creation parent would not have to be stored in an instance 
variable and thus no cyclic reference would arise.

-transami