handle error in position

src/position.rs

@@ -11,22 +11,22 @@ pub struct Position {
 impl Error for Position {}
 
 impl FromStr for Position {
-    type Err = ();
+    type Err = String;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let string = s.to_string();
+        let mut parts = s.split(',');
+        let x = parts.next().unwrap().parse();
+        let y = parts.next().unwrap().parse();
 
-        // e.g. "2,5"
-        let xy: Vec<&str> = string.split(',').collect();
-        let x = xy[0].parse().expect("Bad x coordinate supplied for Position");
-
-        if xy.len() < 2 {
-            panic!("Bad position : {}", string);
+        if x.is_err() {
+            Err("bad x supplied for position".to_string())
+        } else if y.is_err() {
+            Err("bad y supplied for position".to_string())
+        } else {
+            let x = x.unwrap();
+            let y = y.unwrap();
+            Ok(Position { x, y })
         }
-
-        let y = xy[1].parse().expect("Bad y coordinate supplied for Position");
-
-        Ok(Position { x, y })
     }
 }