Expand description
restate
restate is a Rust library that provides a simple way of defining and using finite state machines.
Installation
Add the following to your Cargo.toml file:
[dependencies]
restate = "0.1.0-alpha"
Or use
cargo add restate
Usage
restate can be used to define state machines that can transition between different states based on events. Here is an example:
use restate::blocking::*;
#[derive(Debug, Clone, PartialEq, Eq)]
struct Active;
#[derive(PartialEq, Eq)]
enum CountEvent {
Increment,
Decrement,
}
let mut sm = Machine::with_context(0)
.on_next(
Builder::self_transition(Active, CountEvent::Increment).action(
|cx: ContextMut<Active, CountEvent, i32>| {
*cx.context += 1;
},
),
)
.on_next(
Builder::self_transition(Active, CountEvent::Decrement).action(
|cx: ContextMut<Active, CountEvent, i32>| {
*cx.context -= 1;
},
),
)
.start(Active);
sm.send(CountEvent::Increment).unwrap();
sm.send(CountEvent::Increment).unwrap();
sm.send(CountEvent::Increment).unwrap();
sm.send(CountEvent::Decrement).unwrap();
assert_eq!(*sm.context(), 2);
This example creates a state machine with a single state Active and two events Increment and Decrement. It then adds a self-transition for each event that increments or decrements an integer in the machine’s context. Finally, it starts the machine with the Active state, sends some events to it, and checks the final value of the context.
Modules
- Provides a blocking version of the state machine.
- Errors types for the crate.