ch16.031_best

Perl Best Practices the source code

##############################################################################
##   Code fragment (Recommended) from Chapter 16 of "Perl Best Practices"   ##
##     Copyright (c) O'Reilly & Associates, 2005. All Rights Reserved.      ##
##  See: http://www.oreilly.com/pub/a/oreilly/ask_tim/2001/codepolicy.html  ##
##############################################################################


# Standard modules...
use strict;
use warnings;
use IO::Prompt;
use Carp;
use English qw( -no_match_vars );
use Data::Alias;
use Readonly;

my $product = Shimmer->new({ name=>'Shimmer', patent=>987654321 });

package Wax::Floor;
use Class::Std;
{
    # Attributes...
    my %name_of;
    my %patent_of;
 
    sub BUILD {
        my ($self, $ident, $arg_ref) = @_;
 
        $name_of{$ident}   = $arg_ref->{name};
        $patent_of{$ident} = $arg_ref->{patent};
 
        return;
    }
 
    sub DEMOLISH {
        my ($self, $ident) = @_;
 
        warn __PACKAGE__, " cleaning up $name_of{ident $self}";
        delete $name_of{$ident};
        delete $patent_of{$ident};
 
        return;
    }
}
 
package Topping::Dessert;
use Class::Std;
{
    # Attributes...
    my %name_of;
    my %flavour_of;
 
    sub BUILD {
        my ($self, $ident, $arg_ref) = @_;
        
        $name_of{$ident}    = $arg_ref->{name};
        $flavour_of{$ident} = $arg_ref->{flavour};
 
        return;
    }
 
    sub DEMOLISH {
        my ($self, $ident) = @_;
 
        warn __PACKAGE__, " cleaning up $name_of{ident $self}";
        delete $name_of{$ident};
        delete $flavour_of{$ident};
 
        return;
    }
}



package Shimmer;
use Class::Std;
use base qw( Wax::Floor  Topping::Dessert );
{
    # Attributes...
    my %name_of;
    my %patent_of;
 
    sub BUILD {
        my ($class, $ident, $arg_ref) = @_;
        
        $name_of{$ident}    = $arg_ref->{name};
        $patent_of{$ident} = $arg_ref->{patent};
 
        return;
    }
 
    sub DEMOLISH {
        my ($self, $ident) = @_;
 
        warn __PACKAGE__, " cleaning up $name_of{ident $self}";
        delete $name_of{$ident};
        delete $patent_of{$ident};
 
        return;
    }
}