Add json-framed encoding, docs, refactor

crates/items_0/src/items_0.rs

@@ -149,6 +149,7 @@ pub trait Events:
     fn pulses(&self) -> &VecDeque<u64>;
     fn frame_type_id(&self) -> u32;
     fn to_min_max_avg(&mut self) -> Box<dyn Events>;
+    fn to_json_vec_u8(&self) -> Vec<u8>;
     fn to_cbor_vec_u8(&self) -> Vec<u8>;
 }
 
@@ -269,6 +270,10 @@ impl Events for Box<dyn Events> {
         Events::to_min_max_avg(self.as_mut())
     }
 
+    fn to_json_vec_u8(&self) -> Vec<u8> {
+        Events::to_json_vec_u8(self.as_ref())
+    }
+
     fn to_cbor_vec_u8(&self) -> Vec<u8> {
         Events::to_cbor_vec_u8(self.as_ref())
     }

crates/items_0/src/scalar_ops.rs

@@ -169,8 +169,9 @@ fn equal_string(a: &String, b: &String) -> bool {
     a == b
 }
 
-fn add_int<T: ops::AddAssign>(a: &mut T, b: &T) {
-    ops::AddAssign::add_assign(a, todo!());
+fn _add_int<T: ops::AddAssign>(a: &mut T, b: &T) {
+    let _ = b;
+    ops::AddAssign::add_assign(a, err::todoval());
 }
 
 macro_rules! add_int {
@@ -193,22 +194,36 @@ macro_rules! add_string {
 
 macro_rules! div_int {
     ($a:expr, $b:expr) => {
+        // TODO what is this used for?
+
         // TODO for average calculation, the accumulator must be large enough!
         // Use u64 for all ints, and f32 for all floats.
         // Therefore, the name "add" is too general.
         //*$a /= $b;
+        {
+            let _ = $a;
+            let _ = $b;
+        }
     };
 }
 
 macro_rules! div_bool {
     ($a:expr, $b:expr) => {
-        //
+        // TODO what is this used for?
+        {
+            let _ = $a;
+            let _ = $b;
+        }
     };
 }
 
 macro_rules! div_string {
     ($a:expr, $b:expr) => {
-        //
+        // TODO what is this used for?
+        {
+            let _ = $a;
+            let _ = $b;
+        }
     };
 }