Errors - ErrorKind to program exit code

src/errors.rs

@@ -14,6 +14,16 @@ pub enum ErrorKind {
     Runtime,
 }
 
+impl ErrorKind {
+    /// Program exit code based on the kind of error.
+    pub fn exit_code(self) -> u8 {
+        match self {
+            ErrorKind::Scan | ErrorKind::Parse => 65,
+            ErrorKind::Runtime => 70,
+        }
+    }
+}
+
 impl fmt::Display for ErrorKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str(match self {