ch16.032_best_ex16.11

来自「Perl Best Practices the source code」· 11 代码 · 共 56 行

##############################################################################
##   Example 16.11 (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  ##
##############################################################################


#  Example 16-11. Cleaning up object attributes


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


package Book;
use Class::Std;
{
    # Attributes...
    my %title_of;
    my %author_of;
    my %publisher_of;
    my %year_of;
    my %topic_of;
    my %style_of;
    my %price_of;
    my %rating_of;
 
    # and then...
 
    sub DEMOLISH {
        my ($self, $ident) = @_;
 
        # Update library information...
        Library->remove($self);
 
        # Clean up attribute hashes...
        delete $title_of{$ident};
        delete $author_of{$ident};
        delete $publisher_of{$ident};
        delete $year_of{$ident};
        delete $topic_of{$ident};
        delete $style_of{$ident};
        delete $price_of{$ident};
        delete $rating_of{$ident};
 
        return;
    }
}