my %sample = 
(
   [ 1, 2, 3, 4 ] => [ 5, 6, 7, 8 ]
);

my $key;
foreach $key (keys %samples)
{
   my @a = @$key;
   my @b = @{$sample{ $key }};

   print "key=@a\nvalue=@b\n";
}