package Music;
$VERSION = 1.00;
use strict;
use vars qw( $AUTOLOAD );
use Carp;

{
# Encapsulated class data

	my %_attr_data = #		DEFAULT				ACCESSIBILITY
		( _name 		=> [ '???',				'read'],
		  _artist		=> [ '???',				'read'],
		  _publisher	=> [ '???',				'read'],
		  _ISBN		=> [ '???',				'read'],
		  _tracks		=> [ '???',				'read'],
		  _rating		=> [ -1,				'read/write'],
		  _room		=> [ 'uncatalogued',	'read/write'],
		  _shelf 		=> [ "",				'read/write'],
		);
	my $_count = 0;
# Class methods, to operate on encapsulated class data
	
	# Is a specified object attribute accessible in a given mode
	sub _accessible {
		my ($self, $attr, $mode) = @_;
		$_attr_data{$attr}[1] =~ /$mode/
	}
	
	# Classwide default value for a specified object attribute
	sub _default_for {
		my ($self, $attr) = @_;
		$_attr_data{$attr}[0];
	}
	
	# List of names of all specified object attributes
	sub _standard_keys {
		keys %_attr_data;
	}