[darcs-users] Are there external difinitions in darcs?

[Alexey N. Solofnenko]

The reason why we use them is to avoid duplication and to have a better 
control of versions of dependencies. With ClearCase we put inter VOB (~ 
inter repository) symbolic links within our repository and in config 
spec we specify what revisions (labels) should be used for each 
repository. In short, with ClearCase it is possible to load any subset 
of any repository withing another repository and easily modify/check in 
files from different repositories. This is closer to a configuration 
control, not just revision control. This feature is extremely useful and 
it will be a required feature if we decide to switch from ClearCase.

- Alexey.

Yuval Kogman wrote:

>On Wed, Mar 02, 2005 at 15:19:07 -0800, Alexey N. Solofnenko wrote:
>  
>
>>Hello,
>>
>> We are using them with ClearCase a lot and I just found that 
>>Subversion supports them:
>>
>>http://scm.sipfoundry.org/svndoc/ch07s03.html
>>    
>>
>
>Someone, I think Tom Moertel noted that he noticed a darcs
>convention of constructing a repo like this:
>
>	$ mkdir repo
>	$ cd repo
>	$ darcs init
>	$ mkdir MyProject
>
>and keeping all the files under MyProject inside the repo.
>
>Since patches are pretty much freeform- you can move them in and out
>of repos, and if they can be applied darcs is happy, youc an just
>pull patches from different repositories with different underlying
>directory structures in this manner.
>
>The patches won't conflict since they are not bound to chronology,
>but rather to topology.
>
>I think this is only going to be a source of confusion, though.
>Where do you send which patch? Which is the default repo? etc, etc.
>
>This is, as I gather, the actual feature in external properties.
>Using darcs as an underlying backend to a wrapped system you could
>certainly whip up something like external defs very quickly.
>
>In my opinion, however, darcs itself should not support these. It is
>not really in sync with the distributed system ideas, or the
>principals of simplicity darcs excels in.
>
>As a site maintained and site enforced policy I reckon it could be
>useful, and possibly it should be in some contrib dir somewhere on
>darcs.net.
>
>
>FYI, and perhaps not on topic, here has also been some discussion
>about nesting actual darcs repos. That may also be relevant, one the
>issues clear up. Maybe this is interesting to you?
>
>
>The way I gather, the necessity of such a feature is so that you can
>pull once, from several repos, without confusing the overall
>structure of the working dir. Since in darcs everything is a repo,
>and you can pull from ~other_user/working_dir, or http://mainline,
>or whatnot, this is against the overall concept.
>
>Perhaps instead you want to put in ~/bin or equiv a pull_all
>command, which is something like
>
>	for repo in `find ~ -type d -name _darcs`; do
>		cd `dirname repo`;
>		darcs pull
>	done
>
>At the bottom line: this doesn't seem like something darcs is meant
>to tackle. I doubt it will be a real feature any time soon.
>
>  
>