lattice_maps

Last-writer-wins and observed-remove CRDT maps for Gleam.

Use this package when replicas need key/value data that can be merged without coordination. lww_map stores string values with timestamp conflict resolution; or_map stores nested CRDT values with observed-remove key semantics.

Installation

gleam add lattice_maps

Quick example

import lattice_maps/lww_map

pub fn main() {
  let map =
    lww_map.new()
    |> lww_map.set("status", "draft", 1)
    |> lww_map.set("status", "published", 2)

  lww_map.get(map, "status")
  // -> Ok("published")
}

Modules

Module	Purpose
`lattice_maps/lww_map`	Last-writer-wins map for string keys and string values.
`lattice_maps/or_map`	Observed-remove map whose values are nested CRDTs.
`lattice_maps/crdt`	Tagged union and specs used by `or_map` to store heterogeneous CRDT values.

Notes

lww_map exposes new, set, get, remove, keys, values, merge, prune, to_json, and from_json.
or_map exposes new, update, get, remove, keys, values, merge, prune, to_json, and from_json.
or_map.merge returns a Result because maps with incompatible nested CRDT specs cannot be merged.
or_map supports delta-state replication with update_with_delta, remove_with_delta, apply_delta, merge_deltas, delta_to_json, and delta_from_json.
crdt.CrdtSpec controls the default nested CRDT created for new keys.

License