[Zope-Coders] Re: [ZODB-Dev] Re: revising layout of ZODB3 checkout

[Steve Alexander]

> - Subversion has "svn diff", similar to "cvs diff".  Arch doesn't yet have
> an equivalent.  That's surprising.

I think arch does have an equivalent.

Here's an excerpt from running 'tla help'. 'tla' is the main arch
implementation. It stands for 'tom lord arch'.

 * Local Cache Commands

   what-changed : report about local changes in a project tree
     file-diffs : show local changes to a file

   ls-pristines : list pristine trees in a project tree
  lock-pristine : lock (or unlock) a pristine tree
   add-pristine : ensure that a project tree has a particular pristine revision
  find-pristine : find and print the path to a pristine revision


> - Subversion takes less effort to learn because it uses a command set 
> similar to that of CVS.  Arch uses different conventions.

I learned to use subversion to do checkouts, checkins, diffs etc. in just a few minutes. I had to do a lot of reading to get started with arch.

I think it will be somewhat easier to get started with arch when there is
better documentation for it. However, there will always be the problem
that arch does things very differently than cvs, and so is more foreign
to people who are used to cvs already.


> - Arch supports private repositories very well.

Arch ought to support pair programming and XP very well. Let's say two
programmers are going on a long plane trip. They can take a laptop with them
and take a copy of the Zope 3 repository. They can work on the plane, and
make regular checkins to their own repository, or roll back to previous
revisions if they make mistakes. When they get home, they can merge their
archive with the main one, if they want to and have rights to do so.


> The one major advantage Arch has over Subversion is the strong support for
> distributed repositories.  If I understand it correctly, it's a very cool
> concept.  Let's say you want to make changes to the Zope source and check
> in those changes so others in your company can get them, but you're not
> ready to check in to the main tree.  With Arch, that's no problem--just
> make a repository within your company that mirrors the main tree.  With
> CVS, you'd need to hassle with vendor imports.  I don't know what you'd do
> with Subversion.

Right. That's another example like my scenario above.

They way we've done this using in the schooltool project is to check the
things we're using from Zope CVS into the schooltool subversion repository
as anonymous CVS checkouts. We can keep our local changes in subversion.
When we want to re-synch our checkouts from the Zope repository, it is just
a matter of doing a subversion checkout, with CVS directories included,
then doing a normal 'cvs up'.

--
Steve Alexander