Support for ordered sequences?

[tslocke]

...does cr-sqlite have any special support for them?

Can always use fractional indexing if not, but I was wondering if they are supported in a more high level way?

Thanks

[tantaman]

Not at the moment. You'll need to use fractional indexing as you suggested.

See the reply below for many gotchas of fractional indexing.

tldr: crsqlite will incorporate first class support for fractional indices in Q1 2023.

[tantaman]

@tslocke, as an update -- we're going to be adding first class support for fractional indexing given there are some problematic edge cases

• running out of precision after 64 inserts in just the right location
• users picking the same fractional index and no longer being able to sort something between those items
• some solutions to fractional indexing will always interleave results, some will not but incur a cost at insertion time

we've been talking through these issues here: https://discord.com/channels/989870439897653248/1052527039523078174

And as another update -- I'll be integrating yjs support next year (likely Q2) so you can store rich text crdts.

We'd originally discussed adding diamond types (#65) but yjs might be the fastest path forward to having something that works and most people are already familiar with yjs.

[tantaman]

We've converged on some approaches in the discord. We also discovered that SQLite supports ordering by recursive relationships in a performant manner which should make RGA (and similar) pretty trivial to implement.

For the direction I think we'll end up going with fractional indices, you can see my thoughts here: https://vlcn.io/blog/fractional-indexing

Still noodling on recursive ordering but current thoughts are here: https://vlcn.io/blog/recursive-ordering

and will likely end up implementing something like https://madebyevan.com/algos/crdt-tree-based-indexing/ but with compression for runs to compactly store documents.

mutable tree hierarchy would be interesting but not something I have time to tackle at the moment.

[tantaman]

For sequences: going to take the simple route and just write a yjs provider that integrates with crsqlite clocks.

I.e., something just like https://github.com/yjs/y-leveldb but targeting sqlite.

We can continue rabbit-holing on more exotic options (#65) in the future.