testing state management

src/state.rs

@@ -0,0 +1,28 @@
+use std::sync::{Arc, Mutex};
+
+pub struct StateManager(fn(Arc<StateManager>));
+
+pub struct State<S>(Arc<StateManager>, Arc<Mutex<S>>);
+
+impl StateManager {
+    pub fn new(recall: fn(Arc<StateManager>)) -> Arc<StateManager> {
+        Arc::new(StateManager(recall))
+    }
+
+    pub fn use_state<S>(self: Arc<Self>, state: S) -> State<S> {
+        State(self.clone(), Arc::new(Mutex::new(state)))
+    }
+}
+
+impl<S> State<S> {
+    pub fn set(&self, to: S) {
+        *self.1.lock().unwrap() = to;
+        (self.0 .0)(self.0.clone())
+    }
+}
+
+impl State<i32> {
+    pub fn get(&self) -> i32 {
+        *self.1.lock().unwrap()
+    }
+}