LATTICE
Conflict-free replicated data types (CRDTs) for Gleam. Battle-tested with property-based tests, targeting both Erlang and JavaScript runtimes.
Installation
gleam add lattice_crdt
Quickstart
import lattice/g_counter
pub fn main() {
// Create counters for two replicas
let counter_a = g_counter.new() |> g_counter.increment("node-a", 1)
let counter_b = g_counter.new() |> g_counter.increment("node-b", 3)
// Merge replicas -- CRDTs converge automatically
let merged = g_counter.merge(counter_a, counter_b)
g_counter.value(merged)
// -> 4
}
Available Types
Counters
| Module | Description |
|---|---|
lattice/g_counter | GCounter – grow-only counter |
lattice/pn_counter | PNCounter – positive-negative counter |
Registers
| Module | Description |
|---|---|
lattice/lww_register | LWWRegister – last-writer-wins register |
lattice/mv_register | MVRegister – multi-value register |
Sets
| Module | Description |
|---|---|
lattice/g_set | GSet – grow-only set |
lattice/two_p_set | TwoPSet – two-phase set with add/remove-once |
lattice/or_set | ORSet – observed-remove set |
Maps
| Module | Description |
|---|---|
lattice/lww_map | LWWMap – last-writer-wins map |
lattice/or_map | ORMap – observed-remove map |
Supporting
| Module | Description |
|---|---|
lattice/version_vector | VersionVector – logical clocks for causality tracking |
lattice/dot_context | DotContext – causal context for OR-types |
Features
- Property-based tested merge semantics (commutativity, associativity, idempotency)
- Erlang and JavaScript target support
- JSON serialization for all types
- Comprehensive documentation with examples
Documentation
Full API documentation is available at https://hexdocs.pm/lattice_crdt.
License
MIT - see LICENSE for details.