Damm algorithm

sub damm ( *@digits ) {
    my @tbl = [0, 3, 1, 7, 5, 9, 8, 6, 4, 2],
              [7, 0, 9, 2, 1, 5, 4, 8, 6, 3],
              [4, 2, 0, 6, 8, 7, 1, 3, 5, 9],
              [1, 7, 5, 0, 9, 8, 3, 4, 2, 6],
              [6, 1, 2, 3, 0, 4, 5, 9, 7, 8],
              [3, 6, 7, 4, 2, 0, 9, 5, 8, 1],
              [5, 8, 6, 9, 7, 2, 0, 1, 3, 4],
              [8, 9, 4, 5, 3, 6, 2, 0, 1, 7],
              [9, 4, 3, 8, 6, 1, 7, 2, 0, 5],
              [2, 5, 8, 1, 4, 3, 6, 7, 9, 0];
    my $row = 0;
    for @digits -> $col { $row = @tbl[$row][$col] }
    not $row
}

# Testing
for 5724, 5727, 112946 {
    say "$_:\tChecksum digit { damm( $_.comb ) ?? '' !! 'in' }correct."
}

Output:

5724:   Checksum digit correct.
5727:   Checksum digit incorrect.
112946: Checksum digit correct.