https://alarmingdevelopment.org/?p=1570

Skip to content
Alarming Development

Alarming Development

Dispatches from the User Liberation Front

Posted on October 19, 2021 by Jonathan Edwards

Version Control for Structure Editing

That's the headline for my latest project (with Tomas Petricek),
presented at HATRA. [paper] [recorded talk]

With this work I am finally confronting the demon cursing my work:
version control. If we are to liberate programming from text we need
to make structure editing work, including version control. After all,
there will be limited benefit from structure editing if collaboration
forces us to return to text editing. It feels like this chronic
problem has been dragging me down forever. I've spent endless effort
trying to handle differencing and merging with embedded unique IDs,
but I never got it fully worked out, and it remained as technical
"dark matter" clogging all my projects. I finally had to accept that
the whole approach wasn't working, and start over.

I've turned to the idea of Operational Transformation (OT), which is
how Google Docs works. But OT does synchronization, not version
control, so I've repurposed and generalized it to support long-lived
variants with difference inspection and manual merging. Surprisingly,
it seems no one has done this before, and I had to invent a new
theory.

The result is "high-level" version control. By observing the history
of edits we can do much more intelligent version control. For example
a rename refactoring is a single atomic operation that does not
conflict with any other, whereas in textual VC it conflicts with
every change on the same line as an instance of the name. There is
also a big opportunity to simplify the conceptual model of version
control, which is frankly an utter disaster in git. Perhaps version
control is actually the weak point of the textual edifice, where we
might be able to win a battle.

The paper situates our work as reviving the "image-based" programming
model of Smalltalk and LISP machines and other beloved systems like
HyperCard. Images combied all code and data into harmonious and
habitable programming worlds. But he difficulty of collaboration and
distribution were major blockers for image-based systems. Because
images combine code and data, we must also deal with schema change,
which we talk about in the paper. We see schema change as another
overlooked benefit to structure editing to help incentivize the move
from text.

We have a long way to go towards that vision, but at least this paper
is a concrete step. I haven't published a paper in ages. Thanks to
Tomas for helping me reboot.

Share this:

  * Twitter
  * Email
  * 

CategoriesGeneral

Leave a Reply Cancel reply

Post navigation

Previous PostPrevious I wrote a paper

Links

  * About me
  * Email me
  * Subtext

Meta

  * Log in
  * Entries feed
  * Comments feed
  * WordPress.org

Subscribe to Blog via Email

Email Address [                    ]

Subscribe

Archives

Archives [Select Month  ]

Twitter

My Tweets

  * RSS - Posts
  * RSS - Comments

Follow Us

Proudly powered by WordPress
Send to Email Address [                    ] Your Name
[                    ] Your Email Address [                    ]
[                         ] loading [Send Email] Cancel
Post was not sent - check your email addresses!
Email check failed, please try again
Sorry, your blog cannot share posts by email.