sub isEmpty
{
  return defined $_[0] ? !length($_[0]) : 1;
}

##</code><code>##

sub isEmpty
{
  defined $_[0] or return 1;
  return !($_[0] =~ tr|||c);
}

##</code><code>##

sub isEmpty
{
  return !(defined $_[0] && $_[0] =~ m/./);
}