package Encoder;

## Basic constructor
sub new {
   my $type = shift;
   my $self = {};
   bless $self, $type;
}

## Define the common interface
sub shared_stuff { return reverse $_[1]; }

## Define the uncommon interface
sub other_stuff { 
   die "Somebody didn't define the other stuff!"; 
}

## Generalized encoding method
sub encode {
   my $self = shift;
   my ($text) = @_;

   $self->common_stuff($text);
   $self->other_stuff($text);
}