generate terminal updates with conventional diff/delta algorithms?

I've had this idea kicking around for a while.

Mosh currently generates display updates with ad-hoc code in Terminal::Display::new_frame() and Terminal::Display::put_row(). This code generates strings to update a terminal by comparing individual cells, with some lookahead down the row, and there's also some optimization for scrolling rows. It's rather complicated stuff and a bit fragile.

It seems possible to apply conventional differencing/delta algorithms to a framebuffer, either at a single level treating the entire framebuffer as a single long string, or at two levels-- complete rows and characters within each row. Each character cell, complete with Unicode code points and attributes, would be treated as a single symbol by the diff algorithm.

I'm not sure this would actually be an improvement, but it might get us simpler code and more compact diffs (display updates), and seems worth a closer look.

Another idea is to transmit generalized deltas from server to client, rather than terminal-oriented update strings. That would be a huge, incompatible change, called mosh2 :)

Start by reading Terminal::Display::new_frame() and Terminal::Display::put_row(), where the current cell comparison, lookahead, and scrolling optimizations live. Evaluate whether a conventional framebuffer or row-level diff can simplify the implementation or reduce display updates; done would require a measured comparison and a clear recommendation, since the issue is exploratory.