Try to build better error handling and wrapping with std

d07/src/utils.rs

@@ -1,25 +1,59 @@
 use std::fmt;
 use std::str::FromStr;
 
+#[derive(Debug)]
+struct NestedParseError {
+    message: String,
+    wraps: Option<Box<dyn std::error::Error + 'static>>,
+}
+
+impl fmt::Display for NestedParseError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+impl NestedParseError {
+    fn new(message: &str) -> Self {
+        NestedParseError {
+            message: String::from(message),
+            wraps: None,
+        }
+    }
+
+    fn new_wraps(message: &str, wraps: Box<dyn std::error::Error>) -> Self {
+        NestedParseError {
+            message: String::from(message),
+            wraps: Some(wraps),
+        }
+    }
+}
+
 /// Returns a vector of items parsed from a delimited string
 ///
 /// # Arguments
 ///
 /// * `input` input string to split and parse from
 /// * `delimiter` item delimiter
-pub fn parse_delimited<T>(input: &str, delimiter: &str) -> Vec<T>
+pub fn parse_delimited<T>(input: &str, delimiter: &str) -> Result<Vec<T>, NestedParseError>
 where
     T: FromStr,
-    <T as FromStr>::Err: fmt::Debug,
+    <T as FromStr>::Err: std::error::Error,
 {
-    input
+    let results: Vec<Result<T, <T as FromStr>::Err>> = input
         .split(delimiter)
-        .map(|v| {
+        .map(|v| v.trim().parse::<T>())
-            v.trim()
+        .collect();
-                .parse::<T>()
+
-                .expect(format!("Unable to parse '{}' from text '{}'", v, input).as_str())
+    let first_error = results.iter().find_map(|r| r.err());
-        })
+    if let Some(err) = first_error {
-        .collect()
+        return Err(NestedParseError::new_wraps(
+            format!("Error parsing input {}", input).as_str(),
+            err,
+        ));
+    } else {
+        return Ok(results.iter().map(|v| v.unwrap()).collect::<Vec<T>>());
+    }
 }
 
 /// Returns a string with each element of the vector formatted and joined