Reference-crdts Alternatives

reference-crdts reviews and mentions

• CRDTs make multiplayer text editing part of Zed's DNA
  10 projects | news.ycombinator.com | 1 Dec 2022

  > The goog version seems to work well but I have had nothing but frustration with ms word. Bad merges and weird states are typical, particularly from the fat client.

  Argh not getting this stuff right is really frustrating. I've been working on collaborative editing for over a decade now, and I still can't implement any of these algorithms correctly without the help of a fuzz testing. But fuzz testing done right finds all of these problems! There's no excuse!

  Fuzzers work so well here because all of these algorithms have a clear correctness criteria: After syncing, state should always converge to the same result. So its pretty easy to write code which does this in a loop:

  1. Generates some random changes on some fake "peers"

  2. Picks 2 peers at random and sync their changes, using your new fancy synchronization algorithm

  3. Assert that the state has converged between the peers

  I've been working on this stuff for over a decade. I've implemented dozens of these algorithms. And every single time I write a fuzzy boi to check my work I find convergence bugs. Playing whack-a-mole with a fuzzer is a rite of passage for implementing systems like this.

  When your fuzzer runs all night, you should never have lingering convergence bugs like you're describing with Word.

  As an example, here's a simple fuzzer for a reference list CRDT implementation: https://github.com/josephg/reference-crdts/blob/9f4f9c3a97b4...

  The code is so small it almost fits on my laptop screen.

• WebAssembly 2.0 Working Draft
  21 projects | news.ycombinator.com | 19 Apr 2022