Crate finitomata 

Finitomata — finite state machines with rich lifecycle callbacks, persistence, and supervision.

A Rust port of the Finitomata Elixir library, providing compile-time validated FSMs with actor-based supervision via joerl.

Quick Start

use finitomata::{finitomata, Finitomata, FinitomataSupervisor, TransitionResult};

#[finitomata(
    fsm = r#"
        [*] --> idle
        idle --> |start| running
        running --> |stop| idle
        idle --> |shutdown| off
        off --> |confirm| [*]
    "#,
    syntax = "mermaid",
    auto_terminate = true
)]
#[derive(Debug, Clone, Default)]
struct MyFsm;

#[async_trait::async_trait]
impl Finitomata for MyFsm {
    type State = MyFsmState;
    type Event = MyFsmEvent;
    type Payload = String;

    async fn on_transition(
        &mut self, from: &MyFsmState, event: &MyFsmEvent,
        _ep: &String, _sp: &mut String,
    ) -> TransitionResult<MyFsmState, String> {
        // transition logic here
        TransitionResult::Ok(MyFsmState::Running)
    }
}

Re-exports

pub use callbacks::Finitomata;

pub use callbacks::TransitionResult;

pub use engine::TransitContext;

pub use engine::TransitOutcome;

pub use engine::transit;

pub use error::FinitomataError;

pub use error::PersistencyError;

pub use error::ValidationError;

pub use listener::Listener;

pub use listener::NoopListener;

pub use listener::TracingListener;

pub use parser::FsmParser;

pub use parser::ParseError;

pub use parser::ParsedFsm;

pub use parser::ParsedTransition;

pub use persistency::Persistency;

pub use state::BoundedHistory;

pub use state::FsmState;

pub use state::Lifecycle;

pub use supervisor::FinitomataSupervisor;

pub use timer::FsmTimer;

pub use transition::EventKind;

pub use transition::Transition;

pub use transition::TransitionGraph;

Modules

cache

Concurrent in-memory state cache for fast reads without actor round-trips.

callbacks

engine

Core transition engine implementing the Finitomata callback sequence.

error

listener

Transition observer trait and built-in implementations.

parser

persistency

Persistence trait and backends for durable FSM state.

state

supervisor

FSM supervision backed by joerl’s actor system.

timer

Recurring timer for FSM on_timer callbacks.

transition

Structs

ActorSystem

The actor system runtime.

ChildSpec

Child specification for supervised actors.

Pid

Process identifier that uniquely identifies an actor.

RestartIntensity

Restart intensity limits to prevent infinite restart loops.

SupervisorSpec

Supervisor specification.

Enums

RestartStrategy

Restart strategy for supervised actors.

Attribute Macros

finitomata

Procedural macro for defining finite state machines.