+sub parse_pretty_move {
+ my ($pos, $move) = @_;
+ return $pos->{'board'}->parse_pretty_move($move, $pos->{'toplay'});
+}
+
+# Returns a new Position object.
+sub make_move {
+ my ($pos, $from_row, $from_col, $to_row, $to_col, $promo) = @_;
+
+ my $from_square = _pos_to_square($from_row, $from_col);
+ my $to_square = _pos_to_square($to_row, $to_col);
+
+ my $np = {};
+ $np->{'board'} = $pos->{'board'}->make_move($from_row, $from_col, $to_row, $to_col, $promo);
+ if ($pos->{'toplay'} eq 'W') {
+ $np->{'toplay'} = 'B';
+ $np->{'move_num'} = $pos->{'move_num'};
+ } else {
+ $np->{'toplay'} = 'W';
+ $np->{'move_num'} = $pos->{'move_num'} + 1;
+ }
+
+ my $piece = $pos->{'board'}[$from_row][$from_col];
+ my $dest_piece = $pos->{'board'}[$to_row][$to_col];
+
+ # Find out if this was a two-step pawn move.
+ if (lc($piece) eq 'p' && abs($from_row - $to_row) == 2) {
+ $np->{'ep_file_num'} = $from_col;
+ } else {
+ $np->{'ep_file_num'} = -1;
+ }
+
+ # Castling rights.
+ $np->{'white_castle_k'} = $pos->{'white_castle_k'};
+ $np->{'white_castle_q'} = $pos->{'white_castle_q'};
+ $np->{'black_castle_k'} = $pos->{'black_castle_k'};
+ $np->{'black_castle_q'} = $pos->{'black_castle_q'};
+ if ($piece eq 'K') {
+ $np->{'white_castle_k'} = 0;
+ $np->{'white_castle_q'} = 0;
+ } elsif ($piece eq 'k') {
+ $np->{'black_castle_k'} = 0;
+ $np->{'black_castle_q'} = 0;
+ } elsif ($from_square eq 'a1' || $to_square eq 'a1') {
+ $np->{'white_castle_q'} = 0;
+ } elsif ($from_square eq 'h1' || $to_square eq 'h1') {
+ $np->{'white_castle_k'} = 0;
+ } elsif ($from_square eq 'a8' || $to_square eq 'a8') {
+ $np->{'black_castle_q'} = 0;
+ } elsif ($from_square eq 'h8' || $to_square eq 'h8') {
+ $np->{'black_castle_k'} = 0;
+ }
+
+ # 50-move rule.
+ if (lc($piece) eq 'p' || $dest_piece ne '-') {
+ $np->{'time_since_100move_rule_reset'} = 0;
+ } else {
+ $np->{'time_since_100move_rule_reset'} = $pos->{'time_since_100move_rule_reset'} + 1;
+ }
+ $np->{'player_w'} = $pos->{'player_w'};
+ $np->{'player_b'} = $pos->{'player_b'};
+ $np->{'last_move'} = '(move)'; # FIXME
+ return bless $np;
+}
+
+sub _pos_to_square {
+ my ($row, $col) = @_;
+ return sprintf("%c%d", ord('a') + $col, 8 - $row);
+}
+