smlang 0.8.0

A no-std state machine language DSL
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47

//! Looping state machine
//!
//! An example of a state machine which will loop between State 2 and State 3.
//! A picture depicting the state machine can be found in the README.

#![deny(missing_docs)]

use smlang::statemachine;

statemachine! {
    transitions: {
        *State1 + Event1 = State2,
        State2 + Event2 = State3,
        State3 + Event3 = State2,
    }
}

/// Context
pub struct Context;

impl StateMachineContext for Context {}

fn main() {
    let mut sm = StateMachine::new(Context);
    assert!(matches!(sm.state(), &States::State1));

    let r = sm.process_event(Events::Event1);
    assert!(matches!(r, Ok(&States::State2)));

    let r = sm.process_event(Events::Event2);
    assert!(matches!(r, Ok(&States::State3)));

    // Go back in the loop a few time
    let r = sm.process_event(Events::Event3);
    assert!(matches!(r, Ok(&States::State2)));

    let r = sm.process_event(Events::Event2);
    assert!(matches!(r, Ok(&States::State3)));

    let r = sm.process_event(Events::Event3);
    assert!(matches!(r, Ok(&States::State2)));

    // Now we cannot use Event1 again, as it is outside the state machine loop
    let r = sm.process_event(Events::Event1);
    assert!(matches!(r, Err(Error::InvalidEvent)));
    assert!(matches!(sm.state(), &States::State2));
}