package My::Queue;

use strict;
use warnings;

sub new {
  my $class = shift;
  my $size = shift || 7;
  my $self = {};

  $self->{'size'} = $size;
  $self->{'queue'} = [ ];
  $#{$self->{'queue'}} = $size-1;

  bless $self, $class;
  return $self;
}

sub put {
  my $self = shift;
  my @values = @_;

  unshift @{$self->{'queue'}},@values;
  $#{$self->{'queue'}} = $self->{'size'}-1;

  return scalar @values;
}

sub get {
  my $self = shift;
  my $index = shift;

  die ('Queue: Index out of bounds')
        if ($index < 0 or $index > $self->{'size'}-1);

  return $self->{'queue'}->[$index];
}

package main;

use strict;
use warnings;

my $q = My::Queue->new;

$q->put(1,2,3);

print "Nummer 0: " . $q->get(0) . "\n";
print "Nummer 2: " . $q->get(2) . "\n";
#print "Nummer 3: " . $q->get(3) . "\n";  # wirft ein die!
#print "Nummer -9: " . $q->get(-9) . "\n";       # wirft ein die!

$q->put(99,88,77,66,55);

1;