fix: consider promotion a tactical move

3 files changed, 16 insertions, 7 deletions

diff --git a/src/board/move_generation.rs b/src/board/move_generation.rs
index 7669b85..abc603a 100644
--- a/src/board/move_generation.rs
+++ b/src/board/move_generation.rs
@@ -55,9 +55,15 @@ impl Board {
                 // Generalized attack/move pattern for all pieces
                 for target in (move_targets & targets).serialize() {
                     moves.push(Move { source, target, kind });
+                }
+
+                // Promotions
+                if piece_type == Piece::Pawn && tactical_only {
+                    // All promotions are tactical, but target square can be empty
+                    let iter_captures = (move_targets & targets).serialize();
+                    let iter_pushes = (self.attacks.pawn_pushes[color as usize][source as usize] & empty).serialize();
 
-                    // Promotions
-                    if piece_type == Piece::Pawn {
+                    for target in iter_pushes.chain(iter_captures) {
                         if target.rank() == 7 {
                             for promo_type in [Piece::Bishop, Piece::Knight, Piece::Rook, Piece::Queen] {
                                 moves.push(Move { source, target, kind: MoveKind::Promotion(promo_type)})
@@ -152,6 +158,7 @@ impl Board {
                 }
             }
         }
+
         moves
     }
 }
@@ -164,7 +171,7 @@ mod tests {
 
     #[test]
     fn generate_pseudolegal_moves_starting_position() {
-        let mut board = Board::new();
+        let board = Board::new();
         let moves = board.generate_pseudolegal_moves();
         let black_moves = board.generate_pseudolegal_moves();
 
@@ -212,6 +219,7 @@ mod tests {
         // Make sure tactical_only and true_tactical are identical sets
         for mov in tactical_only.iter() {
             assert!(true_tactical.iter().any(|m| *m == *mov));
+            assert!(mov.is_tactical());
         }
         for mov in true_tactical {
             assert!(tactical_only.iter().any(|m| *m == mov));
@@ -219,6 +227,7 @@ mod tests {
 
         // Make sure quiet_only and true_quiet are identical sets
         for mov in quiet_only.iter() {
+            assert!(!mov.is_tactical());
             assert!(true_quiet.iter().any(|m| *m == *mov));
         }
         for mov in true_quiet {
diff --git a/src/grossmeister/move_selector.rs b/src/grossmeister/move_selector.rs
index fa113ce..33f836b 100644
--- a/src/grossmeister/move_selector.rs
+++ b/src/grossmeister/move_selector.rs
@@ -220,7 +220,7 @@ impl Grossmeister {
                     if self.move_selector().stage_moves.moves.is_empty() {
                         let new_stage  =
                             self.move_selector().tactical_moves.iter()
-                            .filter(|(m, score)| m.is_tactical() && *score < 0.0)
+                            .filter(|(_, score)| *score < 0.0)
                             .copied()
                             .collect();
                         self.init_stage(new_stage);
diff --git a/src/moves.rs b/src/moves.rs
index da66247..b338afe 100644
--- a/src/moves.rs
+++ b/src/moves.rs
@@ -27,7 +27,7 @@ impl Move {
 
     /// Tactical move is a move that changes material score
     pub fn is_tactical(&self) -> bool {
-        matches!(self.kind, MoveKind::Capture | MoveKind::EnPassant)
+        matches!(self.kind, MoveKind::Capture | MoveKind::EnPassant | MoveKind::Promotion(_))
     }
 
     pub fn from_notation(mut notation: Chars) -> Self {
@@ -39,7 +39,7 @@ impl Move {
                 'r' => Piece::Rook,
                 'q' => Piece::Queen,
                 'b' => Piece::Bishop,
-                'k' => Piece::Knight,
+                'n' => Piece::Knight,
                 _ => panic!("Illegal promotion piece: {:?}", promotion)
             };
             return Move { source, target, kind: MoveKind::Promotion(piece) }
@@ -56,7 +56,7 @@ impl Display for Move {
                     Piece::Rook => "r",
                     Piece::Queen => "q",
                     Piece::Bishop => "b",
-                    Piece::Knight => "k",
+                    Piece::Knight => "n",
                     _ => panic!("Illegal promotion piece: {:?}", piece)
                 }
             }