smlang 0.8.0

A no-std state machine language DSL
Documentation 
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//! Reference types in events
//!
//! A simple example of a state machine which will get events that contain references.

#![deny(missing_docs)]

use smlang::statemachine;

/// Reference wrapper
#[derive(Clone, Copy, PartialEq, Debug)]
pub struct MyReferenceWrapper<'a>(pub &'a u32);

statemachine! {
    transitions: {
        *State1 + Event1(&'a [u8]) [guard1] / action1 = State2,
        State2 + Event2(MyReferenceWrapper<'b>) [guard2] / action2 = State3,
    }
}

/// Context
pub struct Context;

impl StateMachineContext for Context {
    fn guard1(&self, event_data: &[u8]) -> Result<bool, ()> {
        // Only ok if the slice is not empty
        Ok(!event_data.is_empty())
    }

    fn action1(&mut self, event_data: &[u8]) -> Result<(), ()> {
        println!("Got valid Event Data = {:?}", event_data);
        Ok(())
    }

    fn guard2(&self, event_data: &MyReferenceWrapper) -> Result<bool, ()> {
        Ok(*event_data.0 > 9000)
    }

    fn action2(&mut self, event_data: MyReferenceWrapper) -> Result<(), ()> {
        println!("Got valid Event Data = {}", event_data.0);
        Ok(())
    }
}

fn main() {
    let mut sm = StateMachine::new(Context);

    let result = sm.process_event(Events::Event1(&[])); // Guard will fail
    assert!(matches!(result, Err(Error::TransitionsFailed)));
    let result = sm.process_event(Events::Event1(&[1, 2, 3])); // Guard will pass
    assert!(matches!(result, Ok(&States::State2)));

    let r = 42;
    let result = sm.process_event(Events::Event2(MyReferenceWrapper(&r))); // Guard will fail
    assert!(matches!(result, Err(Error::TransitionsFailed)));

    let r = 9001;
    let result = sm.process_event(Events::Event2(MyReferenceWrapper(&r))); // Guard will pass
    assert!(matches!(result, Ok(States::State3)));
}