implement From for Colour

src/main.rs

@@ -589,20 +589,22 @@ fn test_tile_to_string() {
     assert_eq!(output, expected);
 }
 
-fn colour_from_string(colour: String) -> Colour {
-    let values: Vec<&str> = colour.split(',').collect();
+impl From<String> for Colour {
+    fn from(string: String) -> Colour {
+        let values: Vec<&str> = string.split(',').collect();
 
         let red:   u8 = values[0].parse().unwrap_or(0);
         let green: u8 = values[1].parse().unwrap_or(0);
         let blue:  u8 = values[2].parse().unwrap_or(0);
 
         Colour { red, green, blue }
+    }
 }
 
 #[test]
 fn test_colour_from_string() {
     assert_eq!(
-        colour_from_string("0,255,0".to_string()),
+        Colour::from("0,255,0".to_string()),
         Colour { red: 0, green: 255, blue: 0 }
     );
 }
@@ -635,7 +637,7 @@ fn palette_from_string(palette: String) -> Palette {
     let colour_start_index = if name.is_some() {2} else {1};
 
     let colours = lines[colour_start_index..].iter().map(|&line| {
-        colour_from_string(line.to_string())
+        Colour::from(line.to_string())
     }).collect();
 
     Palette { id, name, colours }