Pass reference values in guards and owned values in actions

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 
+- [breaking] Actions now take owned values
+- [breaking] `state()` now returns a `Result`
 
 ## [v0.6.0] - 2022-11-02
 

examples/dominos.rs

@@ -22,15 +22,15 @@ impl StateMachineContext for Context {
         Some(Events::ToD2)
     }
 
-    fn to_d3(&mut self, _state_data: &Option<Events>) -> Option<Events> {
+    fn to_d3(&mut self, _state_data: Option<Events>) -> Option<Events> {
         Some(Events::ToD3)
     }
 
-    fn to_d4(&mut self, _state_data: &Option<Events>) -> Option<Events> {
+    fn to_d4(&mut self, _state_data: Option<Events>) -> Option<Events> {
         Some(Events::ToD4)
     }
 
-    fn to_d5(&mut self, _state_data: &Option<Events>) -> Option<Events> {
+    fn to_d5(&mut self, _state_data: Option<Events>) -> Option<Events> {
         Some(Events::ToD5)
     }
 }
@@ -67,5 +67,5 @@ fn main() {
     }
 
     // All the dominos fell!
-    assert!(sm.state() == &States::D5);
+    assert!(matches!(sm.state(), Ok(&States::D5)));
 }

examples/event_with_data.rs

@@ -29,7 +29,7 @@ impl StateMachineContext for Context {
         }
     }
 
-    fn action(&mut self, event_data: &MyEventData) {
+    fn action(&mut self, event_data: MyEventData) {
         println!("Got valid Event Data = {}", event_data.0);
     }
 }

examples/event_with_reference_data.rs

@@ -42,7 +42,7 @@ impl StateMachineContext for Context {
         }
     }
 
-    fn action2(&mut self, event_data: &MyReferenceWrapper) {
+    fn action2(&mut self, event_data: MyReferenceWrapper) {
         println!("Got valid Event Data = {}", event_data.0);
     }
 }

examples/ex1.rs

@@ -21,7 +21,7 @@ impl StateMachineContext for Context {}
 
 fn main() {
     let mut sm = StateMachine::new(Context);
-    assert!(sm.state() == &States::State1);
+    assert!(matches!(sm.state(), Ok(&States::State1)));
 
     let r = sm.process_event(Events::Event1);
     assert!(matches!(r, Ok(&States::State2)));
@@ -32,9 +32,9 @@ fn main() {
     // Now all events will not give any change of state
     let r = sm.process_event(Events::Event1);
     assert!(matches!(r, Err(Error::InvalidEvent)));
-    assert!(matches!(sm.state(), &States::State3));
+    assert!(matches!(sm.state(), Ok(&States::State3)));
 
     let r = sm.process_event(Events::Event2);
     assert!(matches!(r, Err(Error::InvalidEvent)));
-    assert!(sm.state() == &States::State3);
+    assert!(matches!(sm.state(), Ok(&States::State3)));
 }

examples/ex2.rs

@@ -22,7 +22,7 @@ impl StateMachineContext for Context {}
 
 fn main() {
     let mut sm = StateMachine::new(Context);
-    assert!(sm.state() == &States::State1);
+    assert!(matches!(sm.state(), Ok(&States::State1)));
 
     let r = sm.process_event(Events::Event1);
     assert!(matches!(r, Ok(&States::State2)));
@@ -43,5 +43,5 @@ fn main() {
     // 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!(sm.state() == &States::State2);
+    assert!(matches!(sm.state(), Ok(&States::State2)));
 }

examples/ex3.rs

@@ -39,7 +39,7 @@ impl StateMachineContext for Context {
 
 fn main() {
     let mut sm = StateMachine::new(Context);
-    assert!(sm.state() == &States::State1);
+    assert!(matches!(sm.state(), Ok(&States::State1)));
 
     println!("Before action 1");
 
@@ -58,5 +58,5 @@ fn main() {
     println!("After action 2");
 
     // Now we are stuck due to the guard never returning true
-    assert!(sm.state() == &States::State2);
+    assert!(matches!(sm.state(), Ok(&States::State2)));
 }

examples/guard_action_syntax.rs

@@ -32,7 +32,7 @@ impl StateMachineContext for Context {
     }
 
     // Action1 has access to the data from Event1, and need to return the state data for State2
-    fn action1(&mut self, _event_data: &MyEventData) -> MyStateData {
+    fn action1(&mut self, _event_data: MyEventData) -> MyStateData {
         todo!()
     }
 
@@ -42,7 +42,7 @@ impl StateMachineContext for Context {
     }
 
     // Action2 has access to the data from State2
-    fn action2(&mut self, _state_data: &MyStateData) {
+    fn action2(&mut self, _state_data: MyStateData) {
         todo!()
     }
 }

examples/guard_action_syntax_with_temporary_context.rs

@@ -35,7 +35,7 @@ impl StateMachineContext for Context {
     }
 
     // Action1 has access to the data from Event1, and need to return the state data for State2
-    fn action1(&mut self, temp_context: &mut u16, _event_data: &MyEventData) -> MyStateData {
+    fn action1(&mut self, temp_context: &mut u16, _event_data: MyEventData) -> MyStateData {
         *temp_context += 1;
 
         MyStateData(1)
@@ -49,7 +49,7 @@ impl StateMachineContext for Context {
     }
 
     // Action2 has access to the data from State2
-    fn action2(&mut self, temp_context: &mut u16, _state_data: &MyStateData) {
+    fn action2(&mut self, temp_context: &mut u16, _state_data: MyStateData) {
         *temp_context += 1;
     }
 }

examples/guard_custom_error.rs

@@ -42,7 +42,7 @@ impl StateMachineContext for Context {
     }
 
     // Action1 has access to the data from Event1, and need to return the state data for State2
-    fn action1(&mut self, _event_data: &MyEventData) -> MyStateData {
+    fn action1(&mut self, _event_data: MyEventData) -> MyStateData {
         todo!()
     }
 
@@ -52,7 +52,7 @@ impl StateMachineContext for Context {
     }
 
     // Action2 has access to the data from State2
-    fn action2(&mut self, _state_data: &MyStateData) {
+    fn action2(&mut self, _state_data: MyStateData) {
         todo!()
     }
 }

examples/input_state_pattern_match.rs

@@ -45,7 +45,7 @@ impl StateMachineContext for Context {}
 fn main() {
     let mut sm = StateMachine::new(Context);
 
-    assert!(sm.state() == &States::Idle);
+    assert!(matches!(sm.state(), Ok(&States::Idle)));
 
     let r = sm.process_event(Events::Charge);
     assert!(matches!(r, Ok(&States::Charging)));
@@ -61,7 +61,7 @@ fn main() {
 
     let r = sm.process_event(Events::Charge);
     assert!(matches!(r, Err(Error::InvalidEvent)));
-    assert!(sm.state() == &States::Charged);
+    assert!(matches!(sm.state(), Ok(&States::Charged)));
 
     let r = sm.process_event(Events::Discharge);
     assert!(matches!(r, Ok(&States::Discharging)));
@@ -71,7 +71,7 @@ fn main() {
 
     let r = sm.process_event(Events::Discharge);
     assert!(matches!(r, Err(Error::InvalidEvent)));
-    assert!(sm.state() == &States::Discharged);
+    assert!(matches!(sm.state(), Ok(&States::Discharged)));
 
     sm = StateMachine::new_with_state(Context, States::Idle);
     let r = sm.process_event(Events::FaultDetected);
@@ -95,17 +95,17 @@ fn main() {
 
     let r = sm.process_event(Events::Charge);
     assert!(matches!(r, Err(Error::InvalidEvent)));
-    assert!(sm.state() == &States::Fault);
+    assert!(matches!(sm.state(), Ok(&States::Fault)));
 
     let r = sm.process_event(Events::Discharge);
     assert!(matches!(r, Err(Error::InvalidEvent)));
-    assert!(sm.state() == &States::Fault);
+    assert!(matches!(sm.state(), Ok(&States::Fault)));
 
     let r = sm.process_event(Events::ChargeComplete);
     assert!(matches!(r, Err(Error::InvalidEvent)));
-    assert!(sm.state() == &States::Fault);
+    assert!(matches!(sm.state(), Ok(&States::Fault)));
 
     let r = sm.process_event(Events::DischargeComplete);
     assert!(matches!(r, Err(Error::InvalidEvent)));
-    assert!(sm.state() == &States::Fault);
+    assert!(matches!(sm.state(), Ok(&States::Fault)));
 }

examples/reuse_action.rs

@@ -25,7 +25,7 @@ impl StateMachineContext for Context {
 
 fn main() {
     let mut sm = StateMachine::new(Context(0));
-    assert!(sm.state() == &States::State1);
+    assert!(matches!(sm.state(), Ok(&States::State1)));
     assert!(sm.context.0 == 0);
 
     // triggers action