Re: [Haskell-cafe] A small Darcs anomoly

On 24/04/2011 06:33 PM, Jason Dagit wrote:

On Sun, Apr 24, 2011 at 2:05 AM, Andrew Coppin mailto:andrewcoppin@btinternet.com> wrote:

So I was a little surprised to discover that... Darcs doesn't actually support doing this. Darcs is only really interested in the result of applying *all* changes in a repo.

It seems daft to me that you would design a sophisticated system for splitting history into independent chunks, and then not let me manipulate them independently.

This is because of a deliberate choice that was made by David Roundy. In darcs, you never have multiple branches within a single darcs repository directory tree.

Yes, this seems clear. I'm just wondering whether or not it's the best design choice.

To get the effect you want, you simply create two repositories. One having only the patches for ghc 6.6 and one having the patches of ghc 7.0 and then you pull just the patches you want from 7.0 into 6.6. There are options to 'darcs get' that help you select the right set of patches to help you create the two repositories.

It does mean that you duplicate information. You have [nearly] the same set of patches stored twice, and you're not really storing the history of the relationship between two branches, only the history of the branch itself.