Implement std::fmt::Display for board

rs/src/main.rs

@@ -11,7 +11,7 @@ fn main() -> Result<(), ()> {
         match input_lines.next() {
             None => break Ok(()),
             Some(line) => match &line.unwrap()[..] {
-                "get_state" => println!("{}", board.to_string()),
+                "get_state" => println!("{}", board),
                 _ => break Err(()),
             },
         }

rs/src/ui.rs

@@ -1,59 +1,53 @@
 use crate::board;
 use crate::board::GridAxis;
 
-impl board::Color {
-    fn to_string(&self) -> String {
+impl std::fmt::Display for board::Color {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
-            board::Color::White => "W".to_string(),
-            board::Color::Black => "B".to_string(),
+            board::Color::White => write!(f, "W"),
+            board::Color::Black => write!(f, "B"),
         }
     }
 }
 
-impl board::PieceType {
-    fn to_string(&self) -> String {
+impl std::fmt::Display for board::PieceType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
-            board::PieceType::Pawn => "P".to_string(),
+            board::PieceType::Pawn => write!(f, "P"),
         }
     }
 }
 
-impl board::Piece {
-    fn to_string(&self) -> String {
-        self.piece_type.to_string() + &self.color.to_string()
+impl std::fmt::Display for board::Piece {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "{}{}", self.piece_type, self.color)
     }
 }
 
-trait GridAxisIO
-where
-    Self: GridAxis,
-{
-    const ALL_CHARS: [char; 8];
-    fn to_string(&self) -> String {
-        Self::ALL_CHARS[self.get_index() as usize].to_string()
+impl std::fmt::Display for board::Rank {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        const ALL_CHARS: [char; 8] = ['1', '2', '3', '4', '5', '6', '7', '8'];
+        write!(f, "{}", ALL_CHARS[self.get_index() as usize])
     }
 }
 
-impl GridAxisIO for board::Rank {
-    const ALL_CHARS: [char; Self::ALL_VALUES.len()] =
-        ['1', '2', '3', '4', '5', '6', '7', '8'];
-}
-
-impl GridAxisIO for board::File {
-    const ALL_CHARS: [char; Self::ALL_VALUES.len()] =
-        ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'];
-}
-
-impl board::Position {
-    fn to_string(&self) -> String {
-        self.file.to_string() + &self.rank.to_string()
+impl std::fmt::Display for board::File {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        const ALL_CHARS: [char; 8] = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'];
+        write!(f, "{}", ALL_CHARS[self.get_index() as usize])
     }
 }
 
-impl board::Board {
-    pub fn to_string(&self) -> String {
-        self.iter()
-            .map(|(position, piece)| piece.to_string() + &position.to_string())
-            .collect()
+impl std::fmt::Display for board::Position {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "{}{}", self.file, self.rank)
+    }
+}
+
+impl std::fmt::Display for board::Board {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        Ok(for (position, piece) in self.iter() {
+            write!(f, "{}{}", piece, position)?
+        })
     }
 }