Dotted revno "algebra"

[Ben Finney]

Eric Siegerman <lists08-bzr at davor.org> writes:

> On Fri, 2010-05-07 at 09:05 +0200, Vincent Ladeuil wrote:
> > That was my question, why do you care about it. Really, I'm sure
> > there are valid reasons and I'd like to understand them.
>
> I don't know if I can quite put it into words, I'm afraid. The best I
> can say is that I want to know where a feature branch came from, as
> much as I want to know where it went (which now that I reread it, is
> just restating in different words what I said before). I guess I want
> to know what state the trunk was in when I decided it was time to work
> on that feature (or bug fix) in the first place.

For my part, I find the branch-point-based revno useful because it is in
terms of what I'm interested in: what is the distance between this merge
and the previous common ancestor along the branch.

It's a measure of conceptual size of the divergence that is now being
resolved. The measure is in two dimensions that I care about: how far
back on this branch, and how far back on the other branch. That's been
helpful many times to me in forming a conceptual model of the potential
impact of what is merged. It's in *addition* to the size and contents of
the diff, and makes the conceptual model richer.

Merge-point-based revnos would be useless for that kind of conceptual
model, and would add nothing of interest.

> Well, if a way is found to make those interior revno components
> more useful to me than they are now, that'd be a bonus.  But if
> no such enhancement is made, I won't feel short changed; I don't
> have a problem with the status quo.
>
> I *will* feel short changed if such an "enhancement" comes at the
> price of losing properties I *do* value -- which is why I chimed
> in on this thread in the first place :-/

+1.

-- 
 \      “On the internet you simply can't outsource parenting.” —Eliza |
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_o__)                                                                  |
Ben Finney