[board] Move bitboard lib to "board"

board/src/position.rs

@@ -0,0 +1,90 @@
+// Eryn Wells <eryn@erynwells.me>
+
+use crate::bitboard::BitBoard;
+use std::fmt;
+
+mod color {
+    const WHITE: u8 = 0;
+    const BLACK: u8 = 1;
+}
+
+mod piece {
+    const PAWN: u8 = 0;
+    const KNIGHT: u8 = 1;
+    const BISHOP: u8 = 2;
+    const ROOK: u8 = 3;
+    const QUEEN: u8 = 4;
+    const KING: u8 = 5;
+}
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+pub struct Position {
+    /// Composite bitboards for all the pieces of a particular color.
+    pieces_per_color: [BitBoard; 2],
+
+    /// Bitboards representing positions of particular piece types per color.
+    pieces_per_type: [[BitBoard; 6]; 2],
+}
+
+impl Position {
+    fn empty() -> Position {
+        Position {
+            pieces_per_color: [BitBoard(0), BitBoard(0)],
+            pieces_per_type: [
+                [
+                    BitBoard(0),
+                    BitBoard(0),
+                    BitBoard(0),
+                    BitBoard(0),
+                    BitBoard(0),
+                    BitBoard(0),
+                ],
+                [
+                    BitBoard(0),
+                    BitBoard(0),
+                    BitBoard(0),
+                    BitBoard(0),
+                    BitBoard(0),
+                    BitBoard(0),
+                ],
+            ],
+        }
+    }
+
+    /// Return a starting position.
+    fn starting() -> Position {
+        let white_pieces = [
+            BitBoard(0x00FF000000000000),
+            BitBoard(0x4200000000000000),
+            BitBoard(0x2400000000000000),
+            BitBoard(0x8100000000000000),
+            BitBoard(0x1000000000000000),
+            BitBoard(0x8000000000000000),
+        ];
+
+        let black_pieces = [
+            BitBoard(0xFF00),
+            BitBoard(0x0042),
+            BitBoard(0x0024),
+            BitBoard(0x0081),
+            BitBoard(0x0010),
+            BitBoard(0x0080),
+        ];
+
+        Position {
+            pieces_per_color: [
+                BitBoard(white_pieces.iter().map(|bb| bb.0).fold(0, |a, b| a | b)),
+                BitBoard(black_pieces.iter().map(|bb| bb.0).fold(0, |a, b| a | b)),
+            ],
+            pieces_per_type: [white_pieces, black_pieces],
+        }
+    }
+
+    fn piece_at_square(&self, sq: &str) {}
+}
+
+impl fmt::Display for Position {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "abcdefg")
+    }
+}