[](https://travis-ci.org/amarpotghan/haskell-crjdt)
# A Conflict-Free Replicated JSON Datatype for Haskell
*crjdt-haskell* provides high level interface to CRDT which is formalised in the [paper](https://arxiv.org/pdf/1608.03960v1.pdf) by Martin Kleppmann and Alastair R. Beresford.
## Documentation
See [haddocks](https://hackage.haskell.org/package/crjdt-haskell).
## Example
```haskell
{-# LANGUAGE OverloadedStrings #-}
module Main where
import Data.Crjdt as C
-- Original state
original :: Command ()
original = (doc .> key "key") =: "A"
-- First replica updates doc["key"] to "B"
replica1 :: Command ()
replica1 = do
original
(doc .> key "key") =: "B"
-- Second replica updates doc["key"] to "C"
replica2 :: Command ()
replica2 = do
original
(doc .> key "key") =: "C"
main :: IO ()
main = do
-- Sync first and second replica
let Right (r1, r2) = sync (1, replica1) (2, replica2)
let replica1' = execEval 1 r1
replica2' = execEval 2 r2
-- Both replicas converge to: {"key": {"B", "C"}}
print (document replica1' == document replica2') -- True
```
## Future work
* Improve documentation
* Aeson support
* Simplify API as described in [second version](https://arxiv.org/abs/1608.03960) of the paper
## LICENSE
Copyright © 2017 Amar Potghan
Distributed under BSD License.