Refactor Context classes

src/main/java/com/team766/framework/ContextWithValue.java

@@ -4,53 +4,14 @@
  * A {@link Context} that also allows the ProcedureWithValues running on it to yield values when
  * running asynchronously.
  */
-public class ContextWithValue<T> extends Context implements LaunchedContextWithValue<T> {
-
-    private T m_lastYieldedValue;
-
-    @SuppressWarnings("unchecked")
-    ContextWithValue(final RunnableWithContextWithValue<T> func, final Context parentContext) {
-        super((context) -> func.run((ContextWithValue<T>) context), parentContext);
-    }
-
-    @SuppressWarnings("unchecked")
-    ContextWithValue(final RunnableWithContextWithValue<T> func) {
-        super((context) -> func.run((ContextWithValue<T>) context));
-    }
-
-    /**
-     * Return the most recent value passed to yield(T).
-     *
-     * Implements LaunchedContextWithValue<T>
-     */
-    @Override
-    public T lastYieldedValue() {
-        return m_lastYieldedValue;
-    }
-
-    /**
-     * Return the most recent value passed to yield(T), and clear the recorded last yielded value
-     * such that subsequent calls to lastYieldedValue() will return null.
-     *
-     * Implements LaunchedContextWithValue<T>
-     */
-    @Override
-    public T getAndClearLastYieldedValue() {
-        final var result = m_lastYieldedValue;
-        m_lastYieldedValue = null;
-        return result;
-    }
-
+public interface ContextWithValue<T> extends Context {
     /**
      * Momentarily pause execution of this Context to allow other Contexts to execute. Execution of
      * this Context will resume as soon as possible after the other Contexts have been given a
      * chance to run.
      *
      * The most recent value passed to this yield(T) method will be returned by subsequent calls to
-     * lastYieldedValue().
+     * LaunchedContextWithValue.lastYieldedValue().
      */
-    public void yield(final T valueToYield) {
-        m_lastYieldedValue = valueToYield;
-        this.yield();
-    }
+    void yield(final T valueToYield);
 }

src/main/java/com/team766/framework/LaunchedContextWithValue.java

@@ -7,17 +7,21 @@
 public interface LaunchedContextWithValue<T> extends LaunchedContext {
     /**
      * Return the most recent value that the Procedure passed to Context.yield(T).
-     *
-     * Implements LaunchedContextWithValue<T>
+     * Return null if a value has never been yielded, or a value has not been yielded since the last
+     * call to getAndClearLastYieldedValue.
      */
     T lastYieldedValue();
 
+    /**
+     * Return true if a has been yielded by the Procedure since since the last call to
+     * getAndClearLastYieldedValue. Return false otherwise.
+     */
+    boolean hasYieldedValue();
+
     /**
      * Return the most recent value that the Procedure passed to Context.yield(T), and clear the
-     * recorded last yielded value such that subsequent calls to lastYieldedValue() will return
-     * null.
-     *
-     * Implements LaunchedContextWithValue<T>
+     * recorded last yielded value such that subsequent calls to hasYieldedValue() will return
+     * false.
      */
     T getAndClearLastYieldedValue();
 }

src/main/java/com/team766/framework/Mechanism.java

@@ -6,7 +6,7 @@
 import com.team766.logging.Severity;
 
 public abstract class Mechanism extends LoggingBase {
-    private Context m_owningContext = null;
+    private ContextImpl<?> m_owningContext = null;
     private Thread m_runningPeriodic = null;
 
     public Mechanism() {
@@ -44,9 +44,11 @@ public String getName() {
     }
 
     protected void checkContextOwnership() {
-        if (Context.currentContext() != m_owningContext && m_runningPeriodic == null) {
+        if (ContextImpl.currentContext() != m_owningContext && m_runningPeriodic == null) {
             String message =
-                    getName() + " tried to be used by " + Context.currentContext().getContextName();
+                    getName()
+                            + " tried to be used by "
+                            + ContextImpl.currentContext().getContextName();
             if (m_owningContext != null) {
                 message += " while owned by " + m_owningContext.getContextName();
             } else {
@@ -57,7 +59,7 @@ protected void checkContextOwnership() {
         }
     }
 
-    void takeOwnership(final Context context, final Context parentContext) {
+    void takeOwnership(final ContextImpl<?> context, final ContextImpl<?> parentContext) {
         if (m_owningContext != null && m_owningContext == parentContext) {
             Logger.get(Category.FRAMEWORK)
                     .logRaw(
@@ -102,7 +104,7 @@ void takeOwnership(final Context context, final Context parentContext) {
         m_owningContext = context;
     }
 
-    void releaseOwnership(final Context context) {
+    void releaseOwnership(final ContextImpl<?> context) {
         if (m_owningContext != context) {
             LoggerExceptionUtils.logException(
                     new Exception(

src/main/java/com/team766/framework/Scheduler.java

@@ -75,15 +75,15 @@ public void reset() {
     }
 
     public LaunchedContext startAsync(final RunnableWithContext func) {
-        return new Context(func);
+        return new ContextImpl<>(func::run);
     }
 
-    public <T> LaunchedContext startAsync(final RunnableWithContextWithValue<T> func) {
-        return new ContextWithValue<T>(func);
+    public <T> LaunchedContextWithValue<T> startAsync(final RunnableWithContextWithValue<T> func) {
+        return new ContextImpl<T>(func);
     }
 
     public LaunchedContext startAsync(final Runnable func) {
-        return new Context(func);
+        return new ContextImpl<>(func);
     }
 
     public void run() {

src/test/java/com/team766/framework/TimedPredicateTest.java

@@ -11,8 +11,8 @@ public class TimedPredicateTest {
     @Test
     public void testTimedPredicateTimedOut() {
         MockClock testClock = new MockClock(1710411240.0);
-        Context.TimedPredicate predicate =
-                new Context.TimedPredicate(testClock, () -> false, 1.766);
+        ContextImpl.TimedPredicate predicate =
+                new ContextImpl.TimedPredicate(testClock, () -> false, 1.766);
         assertFalse(predicate.getAsBoolean());
         testClock.tick(1.0);
         assertFalse(predicate.getAsBoolean());
@@ -24,8 +24,8 @@ public void testTimedPredicateTimedOut() {
     @Test
     public void testTimedPredicateCondition() {
         MockClock testClock = new MockClock(1710411240.0);
-        Context.TimedPredicate predicate =
-                new Context.TimedPredicate(
+        ContextImpl.TimedPredicate predicate =
+                new ContextImpl.TimedPredicate(
                         testClock,
                         new BooleanSupplier() {
                             private int counter = 0;

src/test/java/com/team766/framework/YieldWithValueTest.java

@@ -14,6 +14,11 @@ private static class ValueConsumer extends Procedure {
         @Override
         public void run(Context context) {
             var generator = context.startAsync(new ValueGenerator());
+
+            assertNull(
+                    generator.lastYieldedValue(),
+                    "lastYieldedValue should be null before the procedure yields a value");
+
             while (generator.lastYieldedValue() == null || generator.lastYieldedValue() < 10) {
                 var value = generator.lastYieldedValue();
                 if (value != null) {