seq maintains state, pop returns changed, none is stop singing

src/flags.rs

@@ -5,7 +5,7 @@ pub struct Flags {
     #[arg(short, long, default_value_t = false)]
     pub debug: bool,
 
-    #[arg(long, default_value_t = 60)]
+    #[arg(long, default_value_t = 120)]
     pub bpm: usize,
 
     #[arg(long, default_value_t = 44100)]
@@ -13,6 +13,9 @@ pub struct Flags {
 
     #[arg(long, default_value = "super_small_font.sf2")]
     pub sound_font: String,
+
+    #[arg(short, long, default_value = "c 2e+")]
+    pub play: Option<String>,
 }
 
 impl Flags {

src/main.rs

@@ -13,10 +13,9 @@ fn main() {
         flags.sound_font,
         flags.sample_rate,
     ));
-    syn_seq.append("c");
-    syn_seq.append("2e");
-    syn_seq.append("g");
-    //syn.tone_on(0, tone::new("c+5"));
+    if let Some(play) = flags.play {
+      syn_seq.append(play);
+    }
 
     play(syn_seq, flags.sample_rate, flags.bpm);
 }

src/seq.rs

@@ -19,9 +19,15 @@ impl SynSeq {
    }
 
    pub fn render(&mut self, left: &mut [f32], right: &mut [f32]) {
-      if let Some(tone) = self.seq.pop() {
-         self.syn.set(tone);
-      }
+      match self.seq.pop() {
+         (Some(tone), changed) if changed => {
+            self.syn.set(0, Some(tone.clone()));
+         },
+         (None, changed) if changed => {
+            self.syn.set(0, None);
+         },
+         _ => {},
+      };
       self.syn.render(left, right);
    }
 
@@ -33,9 +39,10 @@ impl SynSeq {
 #[derive(PartialEq)]
 pub struct Seq {
    beats: Vec<(i32, tone::Tone)>,
+   state: Option<tone::Tone>,
 }
 
-pub fn new() -> Seq {
+fn new() -> Seq {
    Seq::new()
 }
 
@@ -43,10 +50,20 @@ impl Seq {
    fn new() -> Seq {
       Seq{
          beats: vec![],
+         state: None,
       }
    }
 
-   pub fn pop(&mut self) -> Option<tone::Tone> {
+   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();
+      }
+      (tone_after, self.state != state_before)
+   }
+
+   fn _pop(&mut self) -> Option<tone::Tone> {
       match self.beats.len() {
          0 => None,
          _ => match self.beats[0].0 {
@@ -59,8 +76,12 @@ impl Seq {
       }
    }
 
-   pub fn append<S: ToString>(&mut self, s: S) {
-      self.append_one(s.to_string());
+   fn append<S: ToString>(&mut self, s: S) {
+      let s: String = s.to_string();
+      let s: &str = s.as_ref();
+      for split in s.split_whitespace() {
+         self.append_one(split.to_string());
+      }
    }
 
    fn append_one(&mut self, s: String) {
@@ -86,14 +107,22 @@ mod test {
       let mut seq = new();
       seq.append("c");
       seq.append("4d");
-      assert_eq!(seq.beats.len(), 2);
+      seq.append("g 2e");
+      assert_eq!(seq.beats.len(), 4);
       assert_eq!(seq.beats[0], (1 as i32, tone::new("c")));
       assert_eq!(seq.beats[1], (4 as i32, tone::new("d")));
+      assert_eq!(seq.beats[2], (1 as i32, tone::new("g")));
+      assert_eq!(seq.beats[3], (2 as i32, tone::new("e")));
 
-      assert_eq!(seq.pop(), Some(tone::new("c")));
-      for _ in 0..4 {
-         assert_eq!(seq.pop(), Some(tone::new("d")));
+      assert_eq!(seq.pop(), (Some(tone::new("c")), true));
+      assert_eq!(seq.pop(), (Some(tone::new("d")), true));
+      for _ in 1..4 {
+         assert_eq!(seq.pop(), (Some(tone::new("d")), false));
       }
-      assert_eq!(seq.pop(), None);
+      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));
    }
 }

src/syn.rs

@@ -31,46 +31,45 @@ impl Syn {
       Syn::Real(synthesizer)
    }
 
-    pub fn set(&mut self, b: tone::Tone) {
-        let a = 0 as i32;
+   pub fn set(&mut self, ch: i32, b: Option<tone::Tone>) {
       match self {
          // channel=[0..16)
          // velocity=[0..128)
          Syn::Real(syn) => {
-               syn.note_off_all_channel(a, false);
+            syn.note_off_all_channel(ch, false);
          },
          Syn::Text{m, ..} => {
-               m.clear();
+            m.remove(&ch);
          },
       };
-        self.tone_on(b);
+      if let Some(tone) = b {
+         self.tone_on(ch, tone);
+      };
    }
 
-    fn tone_on(&mut self, b: tone::Tone) {
-        let a = 0 as i32;
+   fn tone_on(&mut self, ch: i32, b: tone::Tone) {
       match self {
          // channel=[0..16)
          // velocity=[0..128)
-            Syn::Real(syn) => syn.note_on(a, b.i32(), 127),
+         Syn::Real(syn) => syn.note_on(ch, b.i32(), 127),
          Syn::Text{m, ..} => {
-                match m.get_mut(&a) {
+            match m.get_mut(&ch) {
                Some(m2) => { m2.insert(b.i32(), 127); },
                None => {
                   let mut m2 = std::collections::HashMap::new();
                   m2.insert(b.i32(), 127);
-                        m.insert(a, m2);
+                  m.insert(ch, m2);
                },
             };
          },
       };
    }
 
-    fn tone_off(&mut self, b: tone::Tone) {
-        let a = 0 as i32;
+   fn tone_off(&mut self, ch: i32, b: tone::Tone) {
       match self {
-            Syn::Real(syn) => syn.note_off(a, b.i32()),
+         Syn::Real(syn) => syn.note_off(ch, b.i32()),
          Syn::Text{m, ..} => {
-                match m.get_mut(&a) {
+            match m.get_mut(&ch) {
                Some(m) => { m.remove(&b.i32()); },
                None => {},
             };
@@ -98,10 +97,10 @@ mod test {
    fn test_new_real() {
      let mut syn = Syn::new(false, "super_small_font.sf2".to_string(), 44100);
 
-      syn.tone_on(tone::new("c"));
-      syn.tone_on(tone::new("d"));
+     syn.tone_on(0, tone::new("c"));
+     syn.tone_on(0, tone::new("d"));
 
-      syn.tone_off(tone::new("d"));
+     syn.tone_off(0, tone::new("d"));
 
      let mut buffer1 = Vec::<f32>::new();
      let mut buffer2 = Vec::<f32>::new();
@@ -112,10 +111,10 @@ mod test {
    fn test_text() {
      let mut syn = Syn::new(true, ".sf2".to_string(), 1);
 
-      syn.tone_on(tone::new("c"));
-      syn.tone_on(tone::new("d"));
+     syn.tone_on(0, tone::new("c"));
+     syn.tone_on(0, tone::new("d"));
 
-      syn.tone_off(tone::new("d"));
+     syn.tone_off(0, tone::new("d"));
 
      let mut buffer1 = Vec::<f32>::new();
      let mut buffer2 = Vec::<f32>::new();