Deal with PGNs that do not give out piece information.

[remoteglot] / Board.pm

diff --git a/Board.pm b/Board.pm
index d2a6e0e425f7b48c8584c47e07e1692fd42ab604..91d1a15f7f42b29d5057c2cb9205ae4874a52361 100644 (file)
--- a/Board.pm
+++ b/Board.pm
@@ -148,6 +148,8 @@ sub move_to_uci_notation {
        return _pos_to_square($from_row, $from_col) . _pos_to_square($to_row, $to_col) . $promo;
 }
 
+# Note: This is in general not a validation that the move is actually allowed
+# (e.g. you can castle even though you're in check).
 sub parse_pretty_move {
        my ($board, $move, $toplay) = @_;
 
@@ -175,31 +177,38 @@ sub parse_pretty_move {
        }
 
        $move =~ /^([KQRBN])?([a-h])?([1-8])?x?([a-h][1-8])$/ or die "Invalid move $move";
-       my $piece = $1 // 'P';
+       my $piece = $1;
        my $from_col = defined($2) ? _col_letter_to_num($2) : undef;
        my $from_row = defined($3) ? _row_letter_to_num($3) : undef;
+       if (!defined($piece) && (!defined($from_col) || !defined($from_row))) {
+               $piece = 'P';
+       }
        my ($to_row, $to_col) = _square_to_pos($4);
        
        # Find all possible from-squares that could have been meant.
        my @squares = ();
        my $side = 'K';
        if ($toplay eq 'B') {
-               $piece = lc($piece);
+               $piece = lc($piece) if defined($piece);
                $side = 'k';
        }
        for my $row (0..7) {
                next if (defined($from_row) && $from_row != $row);
                for my $col (0..7) {
                        next if (defined($from_col) && $from_col != $col);
-                       next if ($board->[$row][$col] ne $piece);
-                       next if (!$board->can_reach($piece, $row, $col, $to_row, $to_col));
-
-                       # See if doing this move would put us in check
-                       # (yes, there are clients that expect us to do this).
-                       next if ($board->make_move($row, $col, $to_row, $to_col, $promo)->in_check($side));
+                       next if (defined($piece) && $board->[$row][$col] ne $piece);
                        push @squares, [ $row, $col ];
                }
        }
+       if (scalar @squares > 1) {
+               # Filter out pieces which cannot reach this square.
+               @squares = grep { $board->can_reach($piece, $_->[0], $_->[1], $to_row, $to_col) } @squares;
+       }
+       if (scalar @squares > 1) {
+               # See if doing this move would put us in check
+               # (yes, there are clients that expect us to do this).
+               @squares = grep { !$board->make_move($_->[0], $_->[1], $to_row, $to_col, $promo)->in_check($side) } @squares;
+       }
        if (scalar @squares == 0) {
                die "Impossible move $move";
        }