Re: An idea for versiont racking using translators

[Carl Fredrik Hammar]

Hello,

On Tue, Aug 26, 2008 at 01:15:51PM +0200, Arne Babenhauserheide wrote:
> Hi, 
> 
> This is just a general idea which struck me: 
> 
> With translators it would be easily possible to hide version tracking 
> activity 
> by just stacking a version tracking translator over some directory. 
> 
> A way to control that would then be, to have the translator create virtual 
> files for control. Something like 
> 
> repo_dir/ 
>       .add/
>       .commit
>       .pull
>       .push
>       .remove/
>       .update
>       file1
>       file2
> 
> # Add files
> echo * > .add
> 
> # commit 
> echo "Commit message" > .commit 
> 
> # update to some revision
> echo 123 > .update
> 
> Would easily be possible. 

This is just a clumsier version of the original commands, even worse you
won't get any meaningful error messages if the operation fails.

> There wouldn't be any visible storage dir, since the directory would just be 
> shown as normal file dir with some extra non-standard files. 

Yes, but how would multiple non-standard files better than a single
storage dir?

> Can a translator change how cp works, so that copying such a dir would clone 
> the repo and layer a new translator upon the target (if the target is on a 
> Hurd)? 

It's not possible for a translator to change programs using it, but you
could change the program to treat it specially.  Though I would not
recommend changing cp, since that would be *very* confusing, if it were
suddenly to change behaviour in certain cases.

> Thanks for reading the strange idea until the end. 
> 
> I hope you enjoyed it. :) 

I enjoyed shooting it down.  ;-)

Seriously though, it did get me thinking how useful version control
translators might look like.  The key here is not to try to replace the
command set with a filesystem equivalent, but to supplement it.

It would be very nice if you could set up a translator that showed every
revision in a seperate directory.  Making it almost trivial to browse a
projects history and compare different revisions.  Perhaps even allowing
edits to sanitize history of a personal repo before a major commit to a
public repo.

Another possibility would be a versioning filesystem, were changes to
files are recorded.  This wouldn't be useful as a repo, since there are
no logs and effects are immediate.  But it would be nice to be able to
undo recent changes.

Regards,
  Fredrik