[chora] chora image diff

[Eric Rostetter]

Been meaning to post for several days, never get around to it... Too busy.

Anyway, I think I've departed down the wrong path on this mime-specific
diffing stuff.  

I picked the "side-by-side" diff to change for displaying images side-by-side.
It made some sense in this one case, but doesn't scale well at all.  It 
makes coding things for other mime types much more difficult.  We
could do it, case-by-case, trying to map what we are doing into the existing
categories, but this is really not a very good design.

Also, how is the user to know that "side-by-side" will act differently for
images than everything else?  We could put it in the help/docs, but it
just doesn't seem logical to proceed this way as it isn't intuitive to
the user that things will change based on mime type.

So what I think we should do instead is to add one or more new diff categories
to the existing ones.  We could simply add a "MIME specific" diff entry,
and use that, as long as we don't think any mime type will require more
than one alternate diff format.  I can't think of two many ways to diff
mime-specific items that don't apply generally, so I think we could limit
this to one, or at most two, additional mime-specific tags.

I can also think of some none-mime-specific diff formats we could add
if there is interest, via external programs, like using cmp, comm, etc.

I'd like to start working on that, but won't have any time until later.

I also like the idea of diffing xml files.  I'm willing to work on a
semi-professional version of this.  Or we could require external programs
that do a more professional compare, but I can't find any free software
of that quality, and can't afford the commerical stuff...

Anyway, no time to work on any of this now, but wanted to put it "out
there" anyway...

-- 
Eric Rostetter
The Department of Physics
The University of Texas at Austin

"TAD (Technology Attachment Disorder) is an unshakable, impractical devotion
to a brand, platform, product line, or programming language. It's relatively
harmless among the rank and file, but when management is afflicted the damage
can be measured in dollars. It's also contagious -- someone with sufficient
political clout can infect an entire organization."

--"Enterprise Strategies" columnist Tom Yager.