following some clippy recommendations

src/dialogue.rs

@@ -11,7 +11,7 @@ impl From<String> for Dialogue {
     #[inline]
     fn from(string: String) -> Dialogue {
         let mut lines: Vec<&str> = string.lines().collect();
-        let id = lines[0].replace("DLG ", "").to_string();
+        let id = lines[0].replace("DLG ", "");
 
         let name = if lines.last().unwrap().starts_with("NAME ") {
             Some(lines.pop().unwrap().replace("NAME ", ""))

src/ending.rs

@@ -16,7 +16,7 @@ impl FromStr for Ending {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let lines: Vec<&str> = s.lines().collect();
-        let id = lines[0].replace("END ", "").to_string();
+        let id = lines[0].replace("END ", "");
         let dialogue = lines[1..].join("\n");
 
         Ok(Ending { id, dialogue })

src/game.rs

@@ -6,7 +6,7 @@ use std::str::FromStr;
 use std::collections::HashMap;
 use std::borrow::BorrowMut;
 use std::fmt;
-use std::fmt::Display;
+use std::fmt::{Display, Formatter};
 
 /// in very early versions of Bitsy, room tiles were defined as single alphanumeric characters -
 /// so there was a maximum of 36 unique tiles. later versions are comma-separated.
@@ -25,12 +25,14 @@ impl RoomFormat {
             _   => Err(InvalidRoomFormat),
         }
     }
+}
 
-    fn to_string(&self) -> String {
-        match &self {
+impl Display for RoomFormat {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", match &self {
             RoomFormat::Contiguous     => "0",
             RoomFormat::CommaSeparated => "1",
-        }.to_string()
+        })
     }
 }
 
@@ -826,22 +828,17 @@ impl Game {
     }
 
     fn font_line(&self) -> String {
-        if self.font == Font::AsciiSmall {
-            "".to_string()
-        } else {
-            if self.font == Font::Custom {
-                format!("\n\nDEFAULT_FONT {}", self.custom_font.as_ref().unwrap())
-            } else {
-                format!("\n\nDEFAULT_FONT {}", self.font.to_string().unwrap())
-            }
+        match self.font {
+            Font::AsciiSmall => "".to_string(),
+            Font::Custom     => format!("\n\nDEFAULT_FONT {}", self.custom_font.as_ref().unwrap()),
+            _                => format!("\n\nDEFAULT_FONT {}", self.font.to_string().unwrap()),
         }
     }
 
     fn text_direction_line(&self) -> &str {
-        if self.text_direction == TextDirection::RightToLeft {
-            "\n\nTEXT_DIRECTION RTL"
-        } else {
-            ""
+        match self.text_direction {
+            TextDirection::RightToLeft => "\n\nTEXT_DIRECTION RTL",
+            _ => "",
         }
     }
 

src/room.rs

@@ -67,7 +67,7 @@ impl From<String> for Room {
 
             if last_line.starts_with("WAL") {
                 let last_line = last_line.replace("WAL ", "");
-                let ids: Vec<&str> = last_line.split(",").collect();
+                let ids: Vec<&str> = last_line.split(',').collect();
                 walls = ids.iter().map(|&id| id.to_string()).collect();
             } else if last_line.starts_with("NAME") {
                 name = Some(last_line.replace("NAME ", "").to_string());
@@ -80,8 +80,7 @@ impl From<String> for Room {
                 let position = item_position[1];
                 let position = Position::from_str(position);
 
-                if position.is_ok() {
-                    let position = position.unwrap();
+                if let Ok(position) = position {
                     items.push(Instance { position, id: item_id.to_string() });
                 }
             } else if last_line.starts_with("EXT") {
@@ -89,14 +88,12 @@ impl From<String> for Room {
                 let parts: Vec<&str> = last_line.split(' ').collect();
                 let position = Position::from_str(parts[0]);
 
-                if position.is_ok() {
-                    let position = position.unwrap();
+                if let Ok(position) = position {
                     let exit = Exit::from_str(
                         &format!("{} {}", parts[1], parts[2])
                     );
 
-                    if exit.is_ok() {
-                        let exit = exit.unwrap();
+                    if let Ok(exit) = exit {
                         let mut transition = None;
                         let mut dialogue_id = None;
                         let chunks = parts[3..].chunks(2);
@@ -117,8 +114,7 @@ impl From<String> for Room {
                 let position = ending_position[1];
                 let position = Position::from_str(position);
 
-                if position.is_ok() {
-                    let position = position.unwrap();
+                if let Ok(position) = position {
                     endings.push(Instance { position, id: ending });
                 }
             } else {
@@ -131,8 +127,8 @@ impl From<String> for Room {
         let dimension = lines.len(); // x or y, e.g. `16` for 16x16
         let mut tiles: Vec<String> = Vec::new();
 
-        for line in lines.into_iter() {
-            let comma_separated = line.contains(","); // old room format?
+        for line in lines.iter() {
+            let comma_separated = line.contains(','); // old room format?
             let mut line: Vec<&str> = line
                 .split(if comma_separated {","} else {""})
                 .collect();
@@ -181,8 +177,9 @@ impl Room {
                 tiles.pop(); // remove trailing comma
             }
 
-            tiles.push_str("\n");
+            tiles.push('\n');
         }
+
         tiles.pop(); // remove trailing newline
 
         for instance in &self.items {

src/sprite.rs

@@ -40,10 +40,13 @@ impl Sprite {
     }
 
     fn item_lines(&self) -> String {
-        if self.items.len() == 0 {
+        if self.items.is_empty() {
             "".to_string()
         } else {
-            let lines: Vec<String> = self.items.iter().map(|item| format!("ITM {}", item)).collect();
+            let lines: Vec<String> = self.items.iter().map(
+                |item| format!("ITM {}", item)
+            ).collect();
+
             format!("\n{}", lines.join("\n"))
         }
     }