RosettaCodeData/Task/Align-columns/Perl-6/align-columns-2.pl6

sub MAIN ($alignment where 'left'|'right', $file) {
    my @lines := $file.IO.lines.map(*.split('$').cache).cache;
    my @widths = roundrobin(|@lines).map(*».chars.max);
    my $align  = {left=>'-', right=>''}{$alignment};
    my $format = @widths.map( '%' ~ ++$ ~ '$' ~ $align ~ * ~ 's' ).join(' ') ~ "\n";
    printf $format, |$_ for @lines;
}