Add utility functions for readability and refactor make_move

src/board/board.rs

@@ -167,6 +167,18 @@ impl Board {
     pub fn set_state(&mut self, state: State) {
         self.state = state;
     }
+
+    pub fn piece_type_at(&self, square: usize, color: Color) -> Option<PieceType> {
+        let pieces = match color {
+            Color::White => &self.white_pieces,
+            Color::Black => &self.black_pieces,
+        };
+
+        pieces
+            .iter()
+            .find(|p| have_common_bit(p.bitboard, square_to_bitboard(square)))
+            .map(|p| p.piece_type)
+    }
 }
 
 impl Default for Board {
@@ -216,6 +228,8 @@ impl PieceType {
 }
 use std::ops::{Index, IndexMut};
 
+use super::bitboard::square_to_bitboard;
+
 impl Index<PieceType> for [Piece] {
     type Output = Piece;