Trigger

Seamlessly detect state changes.

Examples

Detect when a variable changes when assigned

// State variable to detect when changed
let mut state = (1, 2.0);

// Assign a different value and on_changed returns true
assert!(trigger::on_changed(&mut state, (2, 2.0)));

// Indeed the state has changed
assert_eq!(state, (2, 2.0));

// Assign the same value and on_changed returns false
assert!(!trigger::on_changed(&mut state, (2, 2.0)));

Detect the rising and falling edges of boolean state

// Boolean state variable
let mut state = trigger::State::default();

// State remains unchanged because its is initialized to false by default
assert!(!state.update(false).changed());

// When updated to true the signal is 'raised'
assert!(state.update(true).raised());

// When updated to true again the signal is unchanged
assert!(!state.update(true).changed());

// When updated to false the signal 'fell'
assert!(state.update(false).fell());

License

Licensed under MIT License, see license.txt.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, shall be licensed as above, without any additional terms or conditions.