ot.js VS collabs

This single file shows the entire set of OT transformations (retain, insert, delete):

https://github.com/Operational-Transformation/ot.js/blob/mas...

and this is a good post outlining the basics of OT, from the creator of CodeMirror:

https://marijnhaverbeke.nl/blog/collaborative-editing-cm.htm...

Thanks! Operational transformation is the same technology that powers Google Docs. It's been studied in academia for real-time collaboration since the 1990s and has eventual consistency guarantees. See the Wikipedia article: https://en.wikipedia.org/wiki/Operational_transformation

The Rust operational-transform library was not written by me, but it's listed on crates.io by spebern, and it's worked wonderfully so far. It seems to be a very close port of ot.js (https://github.com/Operational-Transformation/ot.js). The text transformation algorithm isn't very complicated (<700 SLOC including tests), but there's probably room for optimization!

> Opaque State: [...] You can’t inspect your model represented by the CRDT without using the CRDT library to decode the blob, and you can’t just store the underlying model state because the CRDT needs its change history also. You’re left with an opaque blob of data in your database.

As someone who works on a CRDT library with opaque state [1], I agree that this is a big barrier to adoption. Features like partial loading, per-paragraph permissions, and accept/reject suggestions seem pretty easy to implement if each text char is just a row in your server's DB, but I would have trouble implementing them on top of e.g. Yjs.

For text editing, one idea is to separate the CRDT "positions" from the text itself, which you can then store as a map (position -> char) in your own data structures. I've made a simple (but inefficient) library along these lines [2] and would be interested in ideas for further development.

[1] Collabs - https://collabs.readthedocs.io

[2] position-strings - https://www.npmjs.com/package/position-strings