if ($checks{'data'} =~ /([^$checks{'regex'}])/) {
    bail_out("Bad input.");
  }

##</code><code>##

  my $default = '-\@\w. ';
  $checks{'charclass'} ||= $default;
  my $re = qr/$checks{'charclass'}/is;

   if ($checks{'data'} =~ /[^$re]/) {
      bail_out("Bad data");
   }