Really interesting application of category theory, I'd love to see a nonlinear editor with a good UI. Don't know if the general public would bite, but I think there could be a niche market there.
As an aside, thanks @ColinWright for another high quality submission. HN needs more of these kinds of articles.
Yes, more please! When plumbing gets uninteresting, it does my heart good to see there are still ideas like this I have yet to wrap my brain around. Besides HN and LtU, are there any venues that tend to attract it?
I always wanted a nonlinear editor for representing stuff like different choices of wording in a song or piece of fiction. It never occurred to me that the same idea might work for conflict resolution.
Of course, if branches could be introduced both manually and by editing conflicts, what if there are conflicts in the branches? Would it work to just simulate adding new branches as an incoming conflicting edit?
It looks to me like his scheme would remove the real-time requirement. With Google Docs you'll get unresolvable conflicts when one of the users is editing offline or from a slow network. Recording edits in the described way enables asynchronous conflict resolution, and changes don't have to be submitted in real-time for everyone to get the same document.
No diagrams for exceptions? The diagrams for the text-editing are great, but of you claim that the exception-handling diagrams would look similar, you should draw them.
Or just rename the piece "category theory and text editing" and remove all mention of Exceptions. It would be a complete and good article without the misleading headline.
If these are the kinds of problems that interest you, we're hiring at LiveLoop (http://getliveloop.com). We put real-time collaboration inside Microsoft Office, which is used by over 100 million people every day.
This reminds me of PhD work of Srinivas, using sheaves for KMP style pattern matching. It requires a bit of category theory but the core ideas are accessible. If you google "Sheaves KMP parsing" you can find it in ps format.
As an aside, thanks @ColinWright for another high quality submission. HN needs more of these kinds of articles.