palette to string function

src/main.rs

@@ -517,6 +517,21 @@ fn test_palette_from_string_no_name() {
     assert_eq!(output, expected);
 }
 
+fn palette_to_string(palette: Palette) -> String {
+    let name = if palette.name.is_some() {
+        format!("NAME {}\n", palette.name.unwrap())
+    } else {
+        "".to_string()
+    };
+
+    let colours: Vec<String> = palette.colours.into_iter().map(|colour| {
+        colour_to_string(colour)
+    }).collect();
+    let colours = colours.join("\n");
+
+    format!("PAL {}\n{}{}", palette.id, name, colours)
+}
+
 fn position_from_string(string: String) -> Position {
     // e.g. "2,5"
     let xy: Vec<&str> = string.split(',').collect();