The problems with revisioning stuff in the file:
Assume that no new deltas are added to the file, but the pathname is changed. How do you represent that?
OK, so that is solved, now you have two branches in the tree, with two different pathnames for each branch - how do you associate the pathname with the branch? In other words, how does it generalize? The sun way doesn’t, as far as I can tell because they don’t have any way, that I see, of having a branch in the name graph associated with a branch in the delta graph.
Seems to me there ought to be some way to mix the LOD and pathname namespaces to make this work out.
A more clear statement of the problem:
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I may have any arbitrary object in the file that I want to fork down two parallel lines of development. So I need two name spaces in which to make changes to the objects in a relative way.
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Whatever I do, I need to make sure it works for serial LOD as well as parallel LOD - i.e., release 1 followed by release 2 vs stable vs hacks in parallel.
Solution:
Each thing which is to be revisioned is added as a removed, null delta as a child of the associated revision. In other words, if 1.3 gets Alpha4 then there is a R1.4 (or whatever) that has a tag in the comments that says the symbol is "Alpha". Each addition, deletion, modification of the symbol is a new delta. Changes/additions/deletions are added to the null delta.
The only open issue is the concept of a "default branch" for the case of conflicts.
Actually, we have another open issue which is lines of development. I suspect that the right way to handle this is to make symbols and pathnames be "LOD.pathname" and/or "LOD.symbol" and then there is no confusion - they’ll be on different branches.
So the default branch can be specified as