I think you have the right idea, but possibly the wrong perspective. You want your _source of truth_, which is the "owned data" to be strongly consistent. Your shared data is a "view of truth" which may be incomplete or in disagreement with the source of truth. For example, the color of the sky "right now" depends on where on the earth you are standing, but we can all agree that air is 'just barely blue' and it depends on the light shining into it and how much of there exists.

The _source of truth_ are these facts (like "the air is blue" or "the user inserted the letter A at position X" or "the CPU is 40 degrees"). The view of this source is what we see, and can be seen through a CRDT or any other lens.

▲

josephg 5 days ago | parent [-]

The way I’m defining it, my shared state is the data we store in a crdt. And CRDTs have strong eventual consistency. That’s what makes them great. So we can have a data structure which shows all users an identical view of the world.

Normally we do that by storing something totally different under the hood. Eg, git actually stores a commit graph. But the system makes a determinism guarantee: we promise that all users who have the same version checked out will see exactly the same thing. At one level, we’re storing “a list of facts” (the commit graph). But at another level of abstraction, we’re just storing application data. It’s just also replicated between many peers. And editable locally without network access.

▲

withinboredom 4 days ago | parent [-]

> So we can have a data structure which shows all users an identical view of the world.

This is never true. You can prove that at some time now()-T where T > 0 you had the same view of the universe, but you cannot prove that you currently have the exact same view because even with the attempt of checking, T becomes greater than 0. Sometimes, this doesn't matter (T can be arbitrarily large and still effectively be zero -- like asking your friend if he is still married to that person. They can answer you days later, and it'll still be true), but sometimes even very small values of T cannot be assumed to be zero.

▲

josephg 4 days ago | parent [-]

Well yeah obviously you never know for sure that a remote peer doesn’t have some changes that they haven’t told you about yet. That’s also true with lots of platforms - like google docs and Notion and multiplayer video games. Seems fine though? I don’t understand why this matters for collaborative editing?

▲

withinboredom 4 days ago | parent [-]

Have you ever worked on the same repo with >500 devs? 99% of the time, it doesn’t matter. People talk to people.

	▲	josephg 3 days ago \| parent [-]
		Yes; but I have no idea how that connects to anything else we’ve been discussing here.