errors.pl

use strict;
use warnings;

package Amanda::Changer::Error;
sub new {
  my($class) = @_;
  my $self = {};
  bless($self, $class);
  $self;
}

sub is_fatal {
  0;
}

package Amanda::Changer::Error::Fatal;
use base 'Amanda::Changer::Error';
sub is_fatal {
  1;
}

package main;
my $err = new Amanda::Changer::Error;
print($err->is_fatal? "oh no!\n" : "okay\n");
$err = new Amanda::Changer::Error::Fatal;
print($err->is_fatal? "oh no!\n" : "okay\n");