use Exporter qw{ import };
our @EXPORT = qw( %debug %opt dsay );

our %debug;
our %opt = (d_area => "(default)");

sub dsay( @args ) {
    return
        unless $debug{ uc $opt{d_area} }
            || $debug{'ALL'};
    my $prefix =
        $opt{d_area} ne "(default)"
        ? "DEBUG $opt{d_area}: "
        : "DEBUG: ";
    say $prefix, @args;
}