+ Piece moved_piece = pos->moved_piece(move);
+ std::string pretty;
+ if (type_of(move) == CASTLING) {
+ if (to > from) {
+ pretty = "O-O";
+ } else {
+ pretty = "O-O-O";
+ }
+ } else if (type_of(moved_piece) == PAWN) {
+ if (type_of(move) == ENPASSANT || pos->piece_on(to) != NO_PIECE) {
+ // Capture.
+ pretty = char('a' + file_of(from));
+ pretty += "x";
+ }
+ pretty += UCI::square(to);
+ if (type_of(move) == PROMOTION) {
+ pretty += "=";
+ pretty += " PNBRQK"[promotion_type(move)];
+ }
+ } else {
+ pretty = " PNBRQK"[type_of(moved_piece)];
+ Bitboard attackers = pos->attackers_to(to) & pos->pieces(color_of(moved_piece), type_of(moved_piece));
+ if (more_than_one(attackers)) {
+ // Remove all illegal moves to disambiguate.
+ Bitboard att_copy = attackers;
+ while (att_copy) {
+ Square s = pop_lsb(&att_copy);
+ Move m = make_move(s, to);
+ if (!pos->pseudo_legal(m) || !pos->legal(m)) {
+ attackers &= ~SquareBB[s];
+ }
+ }
+ }
+ if (more_than_one(attackers)) {
+ // Disambiguate by file if possible.
+ Bitboard attackers_this_file = attackers & file_bb(file_of(from));
+ if (attackers != attackers_this_file) {
+ pretty += char('a' + file_of(from));
+ attackers = attackers_this_file;
+ }
+ if (more_than_one(attackers)) {
+ // Still ambiguous, so need to disambiguate by rank.
+ pretty += char('1' + rank_of(from));
+ }
+ }
+
+ if (type_of(move) == ENPASSANT || pos->piece_on(to) != NO_PIECE) {
+ pretty += "x";
+ }
+
+ pretty += UCI::square(to);
+ }
+
+ if (pos->gives_check(move)) {
+ // Check if mate.
+ StateInfo si;
+ pos->do_move(move, si, true);
+ if (MoveList<LEGAL>(*pos).size() > 0) {
+ pretty += "+";
+ } else {
+ pretty += "#";
+ }
+ pos->undo_move(move);