[darcs-devel] Activation Patches

[David Roundy]

On Thu, May 31, 2007 at 07:49:38PM -0700, Jason Dagit wrote:
> >> 2)  An activation patch is its own inverse.  Since the activation
> >> patch does not modify the repository state, it should be clear that
> >> the patch is its own inverse.
> >
> >By similar logic, (_B_) is another inverse of (_A_). Surely that's not
> >true? The inverse of (_A_) must be determined by some semantics that
> >haven't been discussed yet, no?
> 
> Good point.  I'm looking and looking for something else we state or
> discussed that would force the activation patch to be the unique
> inverse of itself.  I cannot think of anything here.  David can you
> think of something?
>
> I would argue that we want an inverse, and we know that the activation
> patch does not change other patches during commutation (and has no
> direct affect on the pristine cache), so the simplest inverse we can
> choose is itself.  So that's exactly what we do.  We take the simplest
> approach.

Correct.  It isn't true that the inverse of (_A_) *must* be (_A_), but it's
the simplest choice.
-- 
David Roundy
Department of Physics
Oregon State University