package foo;
use base qw( Exporter );

my %constants;
use constant +{
	%constants = (
		AAA => 1,
		BBB => 2,
		CCC => 3,
		DDD => 4,
	)
};

our @EXPORT = keys %constants;

1;


package foo2;
use base qw( Exporter );

my %all;
my %foo;
my %bar;
use constant +{
	%all = (
		%foo = (
			AAA => 1,
			BBB => 2,
		),
		%bar = (
			CCC => 3,
			DDD => 4,
		),
	)	
};

our @EXPORT_OK = keys %all;
our %EXPORT_TAGS = (
	all => [ keys %all ],
	foo => [ keys %foo ],
	bar => [ keys %bar ],
);

1;