ch15.028_best

来自「Perl Best Practices the source code」· 028_BEST 代码 · 共 35 行

##############################################################################
##   Code fragment (Recommended) from Chapter 15 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 %selector_of;
my %data_of;

sub clone {
    my ($self) = @_;
 
    # Work out the object's class (and verify that it actually has one)...
    my $class = ref $self
        or croak( qq{Can't clone non-object: $self} );
 
    # Construct a new object, 
    # copying the current object's state into the constructor's argument list...
    return $class->new({ 
        selector => $selector_of{ident $self},
        data     => $data_of{ident $self} 
    });
}