The aim of this library is to implement a (immutable) "rope" data structure based on the one used in xi-editor (authored by Raph Levien).
Xi's rope type is a CRDT (based on WOOT) permitting decentralized collaborative editing without vector clocks.
The ropes are currently implemented and exposed using
Daniel Bünzli's
pvec
library.
My hope is to provide a set of libraries on top of this data structure
supporting n-way merges of application configuration state for MirageOS
unikernels, and a collaborative text editor widget usable with
notty
and mirage-framebuffer
.
Please report any issues or requests for additional features on the issue tracker.
This repository is currently available mainly as a proof of concept, and to enable me to receive feedback on the implementation. As such, this is not production-ready:
-
While the data structures are immutable, it is still quite possible to supply invalid data (cyclic graphs, colliding unique IDs, ..)
-
instead of using
result
types to signal invalid operations, the implementation throws exceptions left and right. -
While the construction, merging and snapshotting are implemented, my underlying implementation is pretty inefficient and some work on that will be needed to support large operations with reasonable performance.
-
insertion is supported, but my algorithms, and the API, to handle insertions are fairly limited and cumbersome to work with.
-
The test suite is missing.- The test suite is missing QuickCheck shrinkers
-
Nice things like Levien's line-wrapping and paging algorithms are not implemented.
Library:
opam pin add -ny pvec https://github.com/dbuenzli/pvec.git
opam install alcotest fmt logs pvec qcheck rresult uchar
Test / demo utils:
opam install notty
dune build
./_build/default/demo/notty_demo.exe
# this will launch a server on 127.0.0.1:7777
# start the program again in another window to have it connect to
# the server. you can now enjoy collaborative editing with
# horribly broken linewrapping where edits from anyone but the server
# gets propagated to the server exclusively. PRs welcome! :-)
Below is a list of resources I found helpful and interesting: