use Perl6::Form;

sub hashes($match,$opts) {
	$opts->{+lfill}='>> ';
	$opts->{+rfill}='<< ';
	return '{I{'.length($match).'}I}';
}

print $^STDOUT, < form
	\%(field=>\@(qr/(#+)/=>\&hashes)),
	"[###|###############################]",
	\@(1,2,3), \qw[First Second Last];