function for optional lines of game data

src/sprite.rs

@@ -1,4 +1,4 @@
-use crate::{AnimationFrames, Image, Position, mock, from_base36, ToBase36};
+use crate::{AnimationFrames, Image, Position, mock, from_base36, ToBase36, optional_data_line};
 
 #[derive(Debug, Eq, PartialEq)]
 pub struct Sprite {
@@ -10,6 +10,16 @@ pub struct Sprite {
     pub position: Position,
 }
 
+impl Sprite {
+    fn name_line(&self) -> String {
+        optional_data_line("NAME", self.name.as_ref())
+    }
+
+    fn dialogue_line(&self) -> String {
+        optional_data_line("DLG", self.dialogue_id.as_ref())
+    }
+}
+
 impl From<String> for Sprite {
     fn from(string: String) -> Sprite {
         let mut lines: Vec<&str> = string.lines().collect();
@@ -59,8 +69,8 @@ impl ToString for Sprite {
             "SPR {}\n{}{}{}\nPOS {} {}",
             self.id.to_base36(),
             self.animation_frames.to_string(),
-            if self.name.as_ref().is_some() { format!("\nNAME {}", self.name.as_ref().unwrap()) } else { "".to_string() },
-            if self.dialogue_id.as_ref().is_some() { format!("\nDLG {}", self.dialogue_id.as_ref().unwrap()) } else { "".to_string() },
+            self.name_line(),
+            self.dialogue_line(),
             self.room_id.to_base36(),
             self.position.to_string(),
         )