{
  my $value;
  my $hash_ref;
  my $done;
  sub get_key {
    unless ($done) {
      (my $key, $value) = each %$hash_ref or # yes, $value is out of scope
        $done = 1;
    }
    defined $key ? $key : "";
  }
  sub get_value {
    defined $value ? $value : "";
  }
  sub set_hash {
    $hash_ref = shift;
    keys %$hash_ref; # reset each()
    $done = 0;
  }
}

set_hash(\%hash_you_want_to_scan);
write STDOUT;

format STDOUT =
@>>>>> @###     @>>>>> @### ~~
get_key(), get_value(), get_key(), get_value()
.