From b9dac0932f9ff85ff468a9b8d2665b1d2badccad Mon Sep 17 00:00:00 2001
From: Max Bradbury <max@tinybird.info>
Date: Mon, 13 Apr 2020 19:08:21 +0100
Subject: [PATCH] function for optional lines of game data

---
 src/lib.rs    | 16 ++++++++++++++++
 src/sprite.rs | 16 +++++++++++++---
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 301e8b7..fce01f9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -30,6 +30,7 @@ use room::Room;
 use sprite::Sprite;
 use tile::Tile;
 use variable::Variable;
+use std::fmt::Display;
 
 #[derive(Debug, Eq, PartialEq)]
 pub struct Instance {
@@ -95,3 +96,18 @@ impl ToBase36 for u64 {
 fn test_to_base36() {
     assert_eq!((37 as u64).to_base36(), "11");
 }
+
+/// e.g. `\nNAME DLG_0`
+fn optional_data_line<T: Display>(label: &str, item: Option<T>) -> String {
+    if item.is_some() {
+        format!("\n{} {}", label, item.unwrap())
+    } else {
+        "".to_string()
+    }
+}
+
+#[test]
+fn test_optional_data_line() {
+    let output = optional_data_line("NAME", mock::item().name);
+    assert_eq!(output, "\nNAME door".to_string());
+}
diff --git a/src/sprite.rs b/src/sprite.rs
index 44df374..19cd59c 100644
--- a/src/sprite.rs
+++ b/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(),
         )