[Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?

[Aaron Bentley]

On Mon, 2003-12-22 at 20:37, michael josenhans wrote:
> > The issue I see is that the current formats are standardized and widely
> > available.  Introducing a plugin architecture would make it hard to know
> > whether you needed additional tools to access a project.
> 
> I can not judge if this is really a threat to arch. It should be easy to 
>   have test cases in place that the diff tool meets the interface 
> requirements. (Patch output format is the interface.)

I believe using an XML diff implies that you must use an XML patch to do
merging.  But there would be no obvious difference bewteen an XML
patching project and a non-XML patching project.  So those without an
XML diff might download half the project before discovering that  they
lacked the necessary tools.

> 
> Plug-ins might it make more difficult than it is today with arch. 
> However I do not think that Arch can be usefully applied to any of those 
> formats that are used with plugins. These are especially those formats 
> written, read and modified by machines. Not by humans as is archs focus 
> today.
> 
> Getting getting arch or patch file type aware and sorting out the 
> requirements we need to automatic merging could be a huge bost to 
> xml-diff and other special purpose diff-tools.

I do not believe fully-automated merging is possible.  What do you do
when one person adds an id=3 attribute to an XHTML tag, and another
person adds an id=4 attribute to the same tag?

> Using Arch with such tools would provide an increaible test bed for 
> those patch tools. The tests arch can do in short time for them, people 
> will likely never be able achieve during life time when using the diff 
> tools manually.

For the moment, you should be able to write a wrapper script around diff
and patch that invokes the proper tool for the proper filetype.  A tar
diff would be interesting, and could probably be written as a script
that invoked diff on each contained file.

Aaron

-- 
Aaron Bentley
Director of Technology
PanoMetrics, Inc.