Improvements from building a sinktask

better type support
cause instead of context,
smoother cuerror building with cause.

Cargo.toml

@@ -11,5 +11,5 @@ members = ["copper",
     "copper_log_runtime",
     "copper_datalogger",
     "copper_clock",
-    "copper_traits", "copper_log_reader"]
+    "copper_traits", "copper_log_reader", "examples/rp-gpio"]
 resolver = "2"

copper/src/config.rs

@@ -25,12 +25,33 @@ impl From<i32> for Value {
         Value(RonValue::Number(value.into()))
     }
 }
+
+impl From<u8> for Value {
+    fn from(value: u8) -> Self {
+        Value(RonValue::Number((value as u64).into()))
+    }
+}
+
 impl From<f64> for Value {
     fn from(value: f64) -> Self {
         Value(RonValue::Number(value.into()))
     }
 }
 
+impl From<Value> for u8 {
+    fn from(value: Value) -> Self {
+        if let RonValue::Number(num) = value.0 {
+            if let Some(i) = num.as_i64() {
+                i as u8
+            } else {
+                panic!("Expected an integer value")
+            }
+        } else {
+            panic!("Expected a Number variant")
+        }
+    }
+}
+
 impl From<Value> for i32 {
     fn from(value: Value) -> Self {
         if let RonValue::Number(num) = value.0 {
@@ -329,7 +350,7 @@ pub fn read_configuration(config_filename: &str) -> CuResult<CuConfig> {
             "Failed to read configuration file: {:?}",
             &config_filename
         ))
-        .add_context(e.to_string().as_str())
+        .add_cause(e.to_string().as_str())
     })?;
     Ok(CuConfig::deserialize_ron(&config_content))
 }

copper_datalogger/src/lib.rs

@@ -91,7 +91,7 @@ impl Stream for MmapStream {
                 _ => {
                     let err =
                         <&str as Into<CuError>>::into("Unexpected error while encoding object.")
-                            .add_context(e.to_string().as_str());
+                            .add_cause(e.to_string().as_str());
                     Err(err)
                 }
             },

copper_derive/src/lib.rs

@@ -99,7 +99,7 @@ pub fn copper_runtime(args: TokenStream, input: TokenStream) -> TokenStream {
                 ty_name, index
             );
             quote! {
-                #ty::new(all_instances_configs[#index]).map_err(|e| e.add_context(#additional_error_info))?
+                #ty::new(all_instances_configs[#index]).map_err(|e| e.add_cause(#additional_error_info))?
             }
         })
         .collect();

copper_traits/src/lib.rs

@@ -6,12 +6,12 @@ use std::fmt::{Display, Formatter};
 #[derive(Debug)]
 pub struct CuError {
     message: String,
-    context: Option<String>,
+    cause: Option<String>,
 }
 
 impl Display for CuError {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        let context_str = match &self.context {
+        let context_str = match &self.cause {
             Some(c) => format!("{}", c),
             None => "None".to_string(),
         };
@@ -26,7 +26,7 @@ impl From<&str> for CuError {
     fn from(s: &str) -> CuError {
         CuError {
             message: s.to_string(),
-            context: None,
+            cause: None,
         }
     }
 }
@@ -35,14 +35,21 @@ impl From<String> for CuError {
     fn from(s: String) -> CuError {
         CuError {
             message: s,
-            context: None,
+            cause: None,
         }
     }
 }
 
 impl CuError {
-    pub fn add_context(mut self, context: &str) -> CuError {
-        self.context = Some(context.into());
+    pub fn new_with_cause(message: &str, cause: impl Error) -> CuError {
+        CuError {
+            message: message.to_string(),
+            cause: Some(cause.to_string()),
+        }
+    }
+
+    pub fn add_cause(mut self, context: &str) -> CuError {
+        self.cause = Some(context.into());
         self
     }
 }