Parse FEN string into game state

src/board.rs

@@ -1,6 +1,7 @@
 use std::fmt;
 use u64 as Bitboard;
 
+#[derive(Debug, PartialEq)]
 pub struct Board {
     white_pieces: [Piece; 6],
     black_pieces: [Piece; 6],
@@ -22,11 +23,45 @@ impl Board {
                 Piece::new(0x8100000000000000, Kind::Rook, Color::Black),
                 Piece::new(0x4200000000000000, Kind::Knight, Color::Black),
                 Piece::new(0x2400000000000000, Kind::Bishop, Color::Black),
-                Piece::new(0x1000000000000000, Kind::Queen, Color::Black),
-                Piece::new(0x800000000000000, Kind::King, Color::Black),
+                Piece::new(0x800000000000000, Kind::Queen, Color::Black),
+                Piece::new(0x1000000000000000, Kind::King, Color::Black),
             ],
         }
     }
+
+    pub fn empty_board() -> Board {
+        Board {
+            white_pieces: [
+                Piece::new(0x0, Kind::Pawn, Color::White),
+                Piece::new(0x0, Kind::Rook, Color::White),
+                Piece::new(0x0, Kind::Knight, Color::White),
+                Piece::new(0x0, Kind::Bishop, Color::White),
+                Piece::new(0x0, Kind::Queen, Color::White),
+                Piece::new(0x0, Kind::King, Color::White),
+            ],
+            black_pieces: [
+                Piece::new(0x0, Kind::Pawn, Color::Black),
+                Piece::new(0x0, Kind::Rook, Color::Black),
+                Piece::new(0x0, Kind::Knight, Color::Black),
+                Piece::new(0x0, Kind::Bishop, Color::Black),
+                Piece::new(0x0, Kind::Queen, Color::Black),
+                Piece::new(0x0, Kind::King, Color::Black),
+            ],
+        }
+    }
+
+    pub fn set_piece(&mut self, piece: Piece) {
+        match piece.color {
+            Color::Black => self.black_pieces[piece.kind as usize].bitboard |= piece.bitboard,
+            Color::White => self.white_pieces[piece.kind as usize].bitboard |= piece.bitboard,
+        };
+    }
+}
+
+impl Default for Board {
+    fn default() -> Self {
+        Self::new()
+    }
 }
 
 impl fmt::Display for Board {
@@ -38,7 +73,7 @@ impl fmt::Display for Board {
                 piece.color, piece.kind
             )?;
         }
-        writeln!(f, "")?;
+        writeln!(f)?;
         for piece in &self.black_pieces {
             writeln!(
                 f,
@@ -46,20 +81,21 @@ impl fmt::Display for Board {
                 piece.color, piece.kind
             )?;
         }
-        write!(f, "")
+        writeln!(f)
     }
 }
 
+#[derive(Debug, PartialEq)]
 pub struct Piece {
-    pub position: Bitboard,
+    pub bitboard: Bitboard,
     pub kind: Kind,
     pub color: Color,
 }
 
 impl Piece {
-    pub fn new(position: Bitboard, kind: Kind, color: Color) -> Piece {
+    pub fn new(bitboard: Bitboard, kind: Kind, color: Color) -> Piece {
         Piece {
-            position,
+            bitboard,
             kind,
             color,
         }
@@ -71,16 +107,16 @@ impl fmt::Display for Piece {
         for rank in (0..8).rev() {
             for file in 0..8 {
                 let square = 1 << (rank * 8 + file);
-                let position = if square & self.position != 0x0 { 1 } else { 0 };
+                let position = if square & self.bitboard != 0x0 { 1 } else { 0 };
                 write!(f, "{} ", position)?;
             }
-            writeln!(f, "")?;
+            writeln!(f)?;
         }
-        write!(f, "")
+        writeln!(f)
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub enum Kind {
     Pawn,
     Rook,
@@ -90,7 +126,7 @@ pub enum Kind {
     King,
 }
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub enum Color {
     White,
     Black,