sub edef {
    my ($symbol) = @_ ;

    no strict 'refs' ;

    my @path = split('::', $symbol) ;
    my $name = pop @path ;

    if (@path == 0) {
      @path = split('::', (caller)[0]) ;  # use caller's package if none given
    } ;

    if (($path[0] eq '') || ($path[0] eq 'main')) {
      shift @path ;    # '::' => 'main::' and we start at 'main::' anyway
    } ;

    my $r_table = \%main:: ;

    foreach my $part (@path) {
      $part .= '::' ;
      if (!exists($r_table->{$part})) { return 0 ; } ;
      $r_table = $r_table->{$part} ;
    } ;

    if (!exists($r_table->{$name})) { return 0 ; } ;

    return defined(${$symbol}) + 2 ;
  } ;