[darcs-users] [Haskell-cafe] Re: poll: how can we help you contribute to darcs?

[Lele Gaifax]

On Thu, 07 Aug 2008 01:41:16 +0900
"Stephen J. Turnbull" <stephen at xemacs.org> wrote:

> Brandon S. Allbery KF8NH writes:
> 
>  > > So if I'm pulling from/pushing to a darcs-2-format repo, my
>  > > local repo must be darcs-2 as well?
>  > 
>  > Given that darcs2 has a different format, that's kinda obvious.
> 
> No, it's not obvious.  In fact, Bazaar does such things (although I
> think mostly in restricted contexts, like "lightweight checkouts").
> 
> It would be nice if someone could explore the possibility of
> transforming patches to push/pull across formats.

It's not (just) a matter of "format": AFAIK, the format itself isn't
changed so much, between darcs-1 and darcs-2 (and I believe that
what's called "hashed" format has actually the same "on-disk"
representation); what's changing between the two is the semantic, that
is, the same patch is handled in a different way, in other words, they
have different meanings. That's why darcs cannot exchange the same
patch between the two semantics (see "Changes in semantics" on
http://wiki.darcs.net/DarcsWiki/DarcsTwo).

> Apparently information would be lost going from darcs2 -> darcs1,
> but it might be enough for people to do gradual migrations to the
> new format.

I'm not aware of such a lost: the primitive patch kinds are the same,
and the metadata that describe the named patches carry the same
information. 

ciao, lele.
-- 
nickname: Lele Gaifax    | Quando vivrò di quello che ho pensato ieri
real: Emanuele Gaifas    | comincerò ad aver paura di chi mi copia.
lele at nautilus.homeip.net |                 -- Fortunato Depero, 1929.