__parent__ - like attribute?

[holger krekel]

Dylan Reinhardt wrote:
> To recap/clarify:
> 
> I have several instances of spam, each of which contains (let's say) many 
> thousands of instances of eggs.  I want for changes made to a single 
> instance of eggs to be made known to the specific instance of spam that 
> contains it.  Similarly, I want for any instance of eggs to be able to get 
> the value of any attribute of its containing spam object.
> 
> To put this more generally, I want a subobject to find its containing 
> object so that methods of the containing object can be called and 
> attributes of the containing object can be set/checked. I gather there's no 
> easy, pre-defined way to do this, so any namespace voodoo that can do the 
> trick would be most welcome.

if you want a contained object to at some point know about its 
container then you should pass the contained object  an explicit 
reference of its container.  This is simple.  

Otherwise, I recommend that you try to come up with a small real 
world example.

    holger