board printing

src/main.rs

@@ -1,7 +1,12 @@
+use repr::{Board, Piece};
+
 mod agent;
 mod game;
 mod repr;
 
 fn main() {
-    println!("Hello, world!");
+    let mut board = Board::new();
+    board.place(0, 1, Piece::Black).unwrap();
+    board.place(0, 3, Piece::White).unwrap();
+    println!("{}", board);
 }

src/repr.rs

@@ -1,3 +1,5 @@
+use std::fmt;
+
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub enum Piece {
     Black,
@@ -11,6 +13,13 @@ impl Piece {
             Piece::White => Piece::Black,
         }
     }
+
+    pub const fn text(&self) -> &'static str {
+        match self {
+            Piece::White => "■",
+            Piece::Black => "□",
+        }
+    }
 }
 
 const BOARD_SIZE: usize = 8;
@@ -20,6 +29,23 @@ pub struct Board {
     board: [[Option<Piece>; BOARD_SIZE]; BOARD_SIZE],
 }
 
+impl fmt::Display for Board {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        for i in 0..BOARD_SIZE {
+            write!(f, "|")?;
+            for j in 0..BOARD_SIZE {
+                write!(
+                    f,
+                    "{}|",
+                    self.get(i, j).as_ref().map(Piece::text).unwrap_or(" ")
+                )?;
+            }
+            write!(f, "\n")?;
+        }
+        Ok(())
+    }
+}
+
 impl Board {
     pub const fn new() -> Self {
         Self {