can play the same note repeatedly

src/seq.rs

@@ -55,7 +55,8 @@ impl SynSeq {
 #[derive(PartialEq)]
 pub struct Seq {
     beats: Vec<(usize, tone::Tone)>,
-    state: Option<tone::Tone>,
+    had_more: bool,
+    eof: bool,
 }
 
 fn new() -> Seq {
@@ -66,7 +67,8 @@ impl Seq {
     fn new() -> Seq {
         Seq {
             beats: vec![],
-            state: None,
+            had_more: false,
+            eof: false,
         }
     }
 
@@ -79,12 +81,22 @@ impl Seq {
     }
 
     fn pop(&mut self) -> (Option<tone::Tone>, bool) {
-        let state_before = self.state.clone();
-        let tone_after = self._pop();
-        if state_before != tone_after {
-            self.state = tone_after.clone();
+        let mut changed = !self.had_more && self.beats.len() > 0;
+        self.had_more = match self.beats.len() {
+            0 => false,
+            _ => self.beats[0].0 > 1,
+        };
+        let eof_before = self.eof;
+        self.eof = self.beats.len() == 0;
+        if !eof_before && self.eof {
+            changed = true;
         }
-        (tone_after, self.state != state_before)
+        let tone = self._pop();
+        eprintln!(
+            " popped ({:?}, {}): had_more={}, beats={:?} eof={} from {}",
+            tone, changed, self.had_more, self.beats, self.eof, eof_before,
+        );
+        (tone, changed)
     }
 
     fn _pop(&mut self) -> Option<tone::Tone> {
@@ -130,20 +142,22 @@ mod test {
     fn test_seq() {
         let mut seq = new();
 
-        seq.append("c");
+        seq.append("c c");
         seq.append("4d");
         seq.append("2-");
         seq.append("g 2e");
 
-        assert_eq!(seq.beats.len(), 5);
-        assert_eq!(seq.len(), 10);
+        assert_eq!(seq.beats.len(), 6);
+        assert_eq!(seq.len(), 11);
 
         assert_eq!(seq.beats[0], (1 as usize, tone::new("c")));
-        assert_eq!(seq.beats[1], (4 as usize, tone::new("d")));
-        assert_eq!(seq.beats[2], (2 as usize, tone::new("!")));
-        assert_eq!(seq.beats[3], (1 as usize, tone::new("g")));
-        assert_eq!(seq.beats[4], (2 as usize, tone::new("e")));
+        assert_eq!(seq.beats[1], (1 as usize, tone::new("c")));
+        assert_eq!(seq.beats[2], (4 as usize, tone::new("d")));
+        assert_eq!(seq.beats[3], (2 as usize, tone::new("!")));
+        assert_eq!(seq.beats[4], (1 as usize, tone::new("g")));
+        assert_eq!(seq.beats[5], (2 as usize, tone::new("e")));
 
+        assert_eq!(seq.pop(), (Some(tone::new("c")), true));
         assert_eq!(seq.pop(), (Some(tone::new("c")), true));
         assert_eq!(seq.pop(), (Some(tone::new("d")), true));
         for _ in 1..4 {
@@ -154,7 +168,7 @@ mod test {
         assert_eq!(seq.pop(), (Some(tone::new("g")), true));
         assert_eq!(seq.pop(), (Some(tone::new("e")), true));
         assert_eq!(seq.pop(), (Some(tone::new("e")), false));
-        assert_eq!(seq.pop(), (None, true));
-        assert_eq!(seq.pop(), (None, false));
+        assert_eq!(seq.pop(), (None, true), "shouldve newly had no more");
+        assert_eq!(seq.pop(), (None, false), "shouldve still had no more");
     }
 }