Add some routines that are useful to parse PGNs.

[remoteglot] / Position.pm

diff --git a/Position.pm b/Position.pm
index e2c9801d7c5957abbaf5eca6eb4437424c6e9887..7834ca065185ad005be02cf06d252756b08dd3ae 100644 (file)
--- a/Position.pm
+++ b/Position.pm
@@ -34,6 +34,11 @@ sub new {
        return $pos;
 }
 
+sub start_pos {
+       my ($class, $white, $black) = @_;
+       return $class->new("<12> rnbqkbnr pppppppp -------- -------- -------- -------- PPPPPPPP RNBQKBNR W -1 1 1 1 1 0 dummygamenum $white $black -2 dummytime dummyincrement 39 39 dummytime dummytime 1 none (0:00) none 0 0 0");
+}
+
 sub fen {
        my $pos = shift;
 
@@ -101,4 +106,74 @@ sub to_json_hash {
        return { %$pos, board => undef, fen => $pos->fen() };
 }
 
+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);
+}
+
 1;