grammar Reversi {
    my $player;
    token TOP         { <game>+ }
    token cell        { \N }
    token board       { [ <cell> ]+ }
    token game        { <board> }
}

my $input = "12345688801234555ZYX------XXOX-----XOO------X-------------------";

for Reversi.parse($input).<game> -> $game {
    my $board = "";
    say $game;
    for $game<board><cell> -> $cell {
        my $c = ++$;
        $board ~= ~$cell;
    }
    say $board;
    say $board.comb(8), "\n";
    say $board.comb(/.**{8}/), "\n";
}