package src::bo::Duck;

use strict;
use warnings;

use Carp;

sub new {
    my $class = shift;
    my $self = {
        FLYBEHAVIOUR => { 'VALUE' => undef, 'ACCESS' => 'protected' },
        QUACKBEHAVIOUR => { 'VALUE' => undef, 'ACCESS' => 'protected' },
    };
    my $closure = sub {
        my $field = shift;
        $self->{$field}->{'ACCESS'} eq 'private' 
            and caller(0) eq __PACKAGE__
            || confess "$field is private";
        $self->{$field}->{'ACCESS'} eq 'protected' 
            and caller(0)->isa(__PACKAGE__)
            || confess "$field is protected";
        if ( @_ ) { $self->{$field}->{'VALUE'} = shift; }
        return $self->{$field}->{'VALUE'};
    };
    bless ($closure, $class);
    return $closure;
}

sub setFlyBehaviour {
    caller(0)->isa(__PACKAGE__) || confess "setFlyBehaviour is protected";
    my $closure      = shift;
    my $flyBehaviour = shift;
    &{ $closure }("FLYBEHAVIOUR", $flyBehaviour);
}
    
sub setQuackBehaviour { 
    caller(0)->isa(__PACKAGE__) || confess "setQuackBehaviour is protected";
    my $closure      = shift;
    my $quackBehaviour = shift;
    &{ $closure }("QUACKBEHAVIOUR", $quackBehaviour);
}
    
sub doFly {
    my $closure = shift;
    &{ $closure }("FLYBEHAVIOUR")->fly();
}

sub doQuack() {
    my $closure = shift;
    &{ $closure }("QUACKBEHAVIOUR")->quack();
}

1;

##</code><code>##

    my $self = {
        FLYBEHAVIOUR => { 'VALUE' => undef, 'ACCESS' => 'protected' },
        QUACKBEHAVIOUR => { 'VALUE' => undef, 'ACCESS' => 'protected' },
    };

##</code><code>##

    my $closure = sub {
        my $field = shift;
        $self->{$field}->{'ACCESS'} eq 'private' 
            and caller(0) eq __PACKAGE__
            || confess "$field is private";
        $self->{$field}->{'ACCESS'} eq 'protected' 
            and caller(0)->isa(__PACKAGE__)
            || confess "$field is protected";
        if ( @_ ) { $self->{$field}->{'VALUE'} = shift; }
        return $self->{$field}->{'VALUE'};
    };

##</code><code>##

$whistle->("QUACKBEHAVIOUR", src::bo::behaviour::quack::CanQuack->new() );

##</code><code>##

sub setFlyBehaviour {
    caller(0)->isa(__PACKAGE__) || confess "setFlyBehaviour is protected";
    my $closure      = shift;
    my $flyBehaviour = shift;
    &{ $closure }("FLYBEHAVIOUR", $flyBehaviour);
}
    
sub setQuackBehaviour { 
    caller(0)->isa(__PACKAGE__) || confess "setQuackBehaviour is protected";
    my $closure      = shift;
    my $quackBehaviour = shift;
    &{ $closure }("QUACKBEHAVIOUR", $quackBehaviour);
}

##</code><code>##

    caller(0) eq __PACKAGE__ || confess "setQuackBehaviour is private";

##</code><code>##

package src::bo::Rubber;

use strict;
use warnings;

use Carp;

use src::bo::Duck;
use base qw/src::bo::Duck/;

use src::bo::behaviour::fly::CannotFly;
use src::bo::behaviour::quack::CanSqeek;

sub new {
    my $class = shift;
    my $extends = $class->SUPER::new( @_ );
    $extends->setFlyBehaviour( src::bo::behaviour::fly::CannotFly->new() );
    $extends->setQuackBehaviour( src::bo::behaviour::quack::CanSqeek->new() );
    my $self = {
        COLOR => { 'VALUE' => undef, 'ACCESS' => 'protected' },
    };
    my $closure = sub {
        my $field = shift;
        if ( exists $self->{$field} ) {
            $self->{$field}->{'ACCESS'} eq 'private'
                and caller(0) eq __PACKAGE__
                || confess "$field is private";
            $self->{$field}->{'ACCESS'} eq 'protected'
                and caller(0)->isa(__PACKAGE__)
                || confess "$field is protected";
            if ( @_ ) { $self->{$field}->{'VALUE'} = shift; }
            return $self->{$field}->{'VALUE'};
        }
        else {
            return $extends->($field,@_);
        }
    };
    bless ($closure, $class);
    return $closure;
}

sub setColor {
    my $closure = shift;
    my $color   = shift;
    &{ $closure }("COLOR", $color );
}

sub getColor {
    my $closure = shift;
    &{ $closure }("COLOR");
}

1;

##</code><code>##

sub new {
    my $class = shift;
    my $extends = $class->SUPER::new( @_ );
    $extends->setFlyBehaviour( src::bo::behaviour::fly::CannotFly->new() );
    $extends->setQuackBehaviour( src::bo::behaviour::quack::CanSqeek->new() );
    my $self = {
        COLOR => { 'VALUE' => undef, 'ACCESS' => 'protected' },
    };
    my $closure = sub {
        my $field = shift;
        if ( exists $self->{$field} ) {
            $self->{$field}->{'ACCESS'} eq 'private'
                and caller(0) eq __PACKAGE__
                || confess "$field is private";
            $self->{$field}->{'ACCESS'} eq 'protected'
                and caller(0)->isa(__PACKAGE__)
                || confess "$field is protected";
            if ( @_ ) { $self->{$field}->{'VALUE'} = shift; }
            return $self->{$field}->{'VALUE'};
        }
        else {
            return $extends->($field,@_);
        }
    };
    bless ($closure, $class);
    return $closure;
}