wip: adding edn parsing to mixer track

crates/tek_mixer/example.edn

@@ -0,0 +1,12 @@
+(mixer
+  (track
+    (name "Drums")
+    (sampler
+      (dir "/home/user/Lab/Music/pak")
+      (sample (midi 34) (name "808 D") (file "808.wav"))))
+  (track
+    (name "Lead")
+    (lv2
+      (name "Odin2")
+      (path "file:///home/user/.lv2/Odin2.lv2"))
+    (gain 0.0)))

crates/tek_mixer/src/mixer_track.rs

@@ -1,4 +1,5 @@
 use crate::*;
+use tek_core::edn;
 
 /// TODO: A track in the mixer. (Integrate with [crate::model::Track]?)
 pub struct MixerTrack {
@@ -52,6 +53,44 @@ impl MixerTrack {
     }
 }
 
+impl MixerTrack {
+    fn load_edn <'a, 'e> (app: &'a mut App, args: &[Edn<'e>]) -> Usually<&'a mut Self> {
+        let ppq = app.transport.ppq();
+        let mut name = None;
+        let mut _gain = 0.0f64;
+        let mut devices: Vec<JackDevice> = vec![];
+        edn!(edn in args {
+            Edn::Map(map) => {
+                if let Some(Edn::Str(n)) = map.get(&Edn::Key(":name")) {
+                    name = Some(*n);
+                }
+                if let Some(Edn::Double(g)) = map.get(&Edn::Key(":gain")) {
+                    _gain = f64::from(*g)
+                }
+            },
+            Edn::List(args) => match args.get(0) {
+                Some(Edn::Symbol("sampler")) => {
+                    devices.push(Sampler::load_edn(&args[1..])?)
+                },
+                Some(Edn::Symbol("lv2")) => {
+                    devices.push(LV2Plugin::load_edn(&args[1..])?)
+                },
+                None => panic!("empty list track {}",
+                    name.unwrap_or("")
+                ),
+                _ => panic!("unexpected in track {}: {:?}",
+                    name.unwrap_or(""),
+                    args.get(0).unwrap()
+                )
+            },
+            _ => {}
+        });
+        let track = app.arranger.track_add(name)?;
+        for device in devices { track.add_device(device)?; }
+        Ok(track)
+    }
+}
+
 //impl<W: Write> Input<TUI<W>, bool> for Mixer {
     //fn handle (&mut self, engine: &mut TUI<W>) -> Result<Option<bool>> {
         //Ok(None)