sub this_deep {
	my ($self, $depth) = @_;
	$depth = -1 unless @_ > 1;
	$self->{depth} = $depth;
}

sub next {
	my $self = shift;
	while( 1 ) {
		if (  @{ $self->{output} }  ) {
			my $line = shift @{ $self->{output} };
			return $line;
		}
		if ( ! @{ $self->{dirs} } ) {
			return;
		}
		my $dir = shift @{ $self->{dirs} };
		if (-d $dir) {
			if(  opendir( DIR, $dir )  ) {
				map {
					my $file = $_;
					my $fullfile = File::Spec->catfile( $dir, $file );
					if (-d $fullfile && ($self->{level} <= $self->{depth} || $self->{depth} == -1)) {
						push (@{ $self->{dirs} }, $fullfile);
					}
				} File::Spec->no_upwards( readdir(DIR) );
				closedir DIR;
				
			} else {
				warn "\a\a\aopendir FAILED, $dir: $!";
			}
		} else {
			warn "\a\a\aNOT A DIRECTORY: $dir\n";
		}
	}
}