fix diagonals and user input

src/board.rs

@@ -12,9 +12,9 @@ impl fmt::Display for Board {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let horiz_sep_line = "-".repeat(BOARD_SIZE * 2 + 1);
         for i in 0..BOARD_SIZE {
-            writeln!(f, "{}", horiz_sep_line)?;
+            writeln!(f, " {}", horiz_sep_line)?;
 
-            write!(f, "|")?;
+            write!(f, "{}|", i)?;
             for j in 0..BOARD_SIZE {
                 write!(
                     f,
@@ -117,7 +117,17 @@ impl Board {
         // handle diagonals
         chains.extend(
             i_chain
+                .clone()
                 .into_iter()
+                .zip(j_chain.clone())
+                .map(|(i_vec, j_vec)| i_vec.into_iter().zip(j_vec).collect()),
+        );
+
+        // handle top right diagonals too
+        chains.extend(
+            i_chain
+                .into_iter()
+                .rev()
                 .zip(j_chain)
                 .map(|(i_vec, j_vec)| i_vec.into_iter().zip(j_vec).collect()),
         );
@@ -240,4 +250,16 @@ mod test {
             );
         }
     }
+
+    #[test]
+    fn diag_capture() {
+        let mut board = Board::new().starting_pos();
+
+        assert_eq!(board.place(2, 4, Piece::White), Ok(()), "{}", board);
+        assert_eq!(board.place(2, 3, Piece::Black), Ok(()), "{}", board);
+
+        assert_eq!(board.place(2, 2, Piece::White), Ok(()), "{}", board);
+
+        assert_eq!(board.place(2, 5, Piece::Black), Ok(()), "{}", board);
+    }
 }