use strict;
use warnings;
use Data::Dumper;

local $Data::Dumper::Deparse = 1;

use constant INVALID_DATA => ( q{invalid}, 0 );
use constant ADD_DATA => ( q{add}, 1 );
use constant REMOVE_DATA => ( q{remove}, 2 );
use constant MODES => ( \&ADD_DATA, \&REMOVE_DATA );

print Dumper [ MODES ];
print Dumper [ (MODES)[0]() ];