feat: error handling (partial)

src/ty/common.rs

@@ -9,16 +9,12 @@ use regex::Regex;
 
 #[derive(Clone, Debug, PartialEq, Constructor)]
 pub struct Catchable {
-    msg: Option<String>,
+    msg: String,
 }
 
 impl Display for Catchable {
     fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
-        if let Some(ref msg) = self.msg {
-            write!(f, "<error: {msg}>")
-        } else {
-            write!(f, "<error>")
-        }
+        write!(f, "<error: {}>", self.msg)
     }
 }