About namespaces and inheritance:

Namespaces, like "Animal::Dog", are just names, as was written before. Inheritance is defined differently, but it is good habit to create namespaces related with inheritance, for instance:

package Animal; #parent class, in file lib/Animal.pm 
sub new {
  return bless {}, shift;
}
sub sound {
  die "cannot call this method on class '".ref(shift)."'";
}
sub output_sound {
  my ($self, $what) = @_;
  print $what."\n";
}
1;

package Animal::Dog; #desc. of Animal, lib/Animal/Dog.pm
use base 'Animal';
sub sound {
  my ($self) = @_;
  $self->output_sound("haf");
}
1;

package Animal::Dog::Sheepdog; #desc. of Dog
                               #lib/Animal/Dog/Sheepdog.pm
use base 'Animal::Dog';
sub guard {
  my ($self, $flock) = @_;
  #do something
}
1;

package Animal::Pig; #other descendant
use base 'Animal';
sub sound {
  my ($self) = @_;
  $self->output_sound("khro");
}
1;
[download]

Now you can create some instance of animal :>) by this way:

use Animal::Dog::Sheepdog;
my $helper = Animal::Dog::Sheepdog->new();

#Once you have an instance, you can call it's methods by this way:

$helper->sound;
[download]

Do not hesitate to ask some questions, I had been confused in the same manner. Just note: that code is not tested, it really should have strictings in every module...

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.