[development] Lineage module --- nested trees

[Earl Miles]

Karoly Negyesi wrote:
>> Interestingly, I initially submitted this as a patch to core and was  
>> immediately told it didn't belong there.
> 
> 
> Well, killes commented in the issue that you will have problems with  
> multiple inheritance. I just pointed out that with hook_taxonomy you 
> could  move this to a module. I was not thinking on other trees, but 
> Dries is  quite right that there are many single inheritance trees in 
> Drupal (we  talked a lot about them) AND many taxonomies are not multi 
> inheritance --  they could benefit from this, too.
> 
> I hope this clarifies what's happened so far.

I think it was the right path, too. What Dries wants out of this -- and I had 
not even thought about -- is a generic algorithm that can be used for any tree. 
It makes a lot of sense, but I was only focused on taxonomy because of what I 
was doing.

A little bit of contemplation is showing me that some thought is going to have 
to go into the design. I will post a draft on the forum later today for 
feedback. There's a couple of different ways to do this and I want to present 
them both (or all if I think of a third) and see what people think.