Assignment 12 Done (Except card.rs)

src/assignments/assignment12/demux.rs

@@ -28,11 +28,25 @@ impl<T, F: Fn(&T) -> bool> DemuxSender<T, F> {
     ///
     ///  If `f(&value)` is true, send `value` to `tx_true`. Otherwise, send `value` to `tx_false`.
     pub fn send(&self, value: T) -> Result<(), SendError<T>> {
-        todo!()
+        if (self.f)(&value) {
+            self.tx_true.send(value)
+        } else {
+            self.tx_false.send(value)
+        }
     }
 }
 
 /// Demux.
 pub fn demux<T, F: Fn(&T) -> bool>(f: F) -> (DemuxSender<T, F>, Receiver<T>, Receiver<T>) {
-    todo!()
+    let (tx_true, rx_true) = channel();
+    let (tx_false, rx_false) = channel();
+    (
+        DemuxSender {
+            tx_true,
+            tx_false,
+            f,
+        },
+        rx_true,
+        rx_false,
+    )
 }

src/assignments/assignment12/funnel.rs

@@ -19,5 +19,18 @@ where
     T: Send + 'static,
     F: Send + Sync + Fn(&T) -> bool + 'static,
 {
-    todo!()
+    let tx = Arc::new(tx);
+    let f = Arc::new(f);
+    thread::spawn(move || {
+        for rx in rxs {
+            let tx = tx.clone();
+            let f = f.clone();
+            let _unused = thread::spawn(move || loop {
+                let v = rx.recv().unwrap();
+                if f(&v) {
+                    tx.send(v).unwrap()
+                }
+            });
+        }
+    })
 }

src/assignments/assignment12/small_exercises.rs

@@ -13,7 +13,9 @@ use etrace::*;
 /// Read the `test_ping_pong` function in `small_exercises_grade.rs` to figure out what it should
 /// do.
 pub fn pong(rx1: &mut Receiver<u32>, tx2: &mut Sender<u32>) -> bool {
-    todo!()
+    let i = rx1.recv().unwrap();
+    tx2.send(i + 1).unwrap();
+    i != 99
 }
 
 /// Executes the given functions (f1, f2) in concurrent and returns the results.
@@ -31,5 +33,7 @@ where
     F1: Send + FnOnce() -> T1 + 'scope,
     F2: Send + FnOnce() -> T2 + 'scope,
 {
-    todo!()
+    let (t1, t2) = (s.spawn(f1), s.spawn(f2));
+    let (v1, v2) = (t1.join(), t2.join());
+    (v1.unwrap(), v2.unwrap())
 }