1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
#!perl
###############################################################################
## ##
## Copyright (c) 2000 - 2013 by Steffen Beyer. ##
## All rights reserved. ##
## ##
## This program is free software; you can redistribute it ##
## and/or modify it under the same terms as Perl itself. ##
## ##
###############################################################################
######################################################################
# #
# How to emulate the Set::Object module using Bit::Vector (example): #
# #
######################################################################
package InheritMe;
use strict;
use vars qw( @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS $VERSION );
require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw();
@EXPORT_OK = qw( RegisterMe ID2Obj Obj2ID Registered );
%EXPORT_TAGS = (all => [@EXPORT_OK]);
$VERSION = 1.0;
my $ID = 0;
my(%id2obj) = ();
my(%obj2id) = ();
sub RegisterMe
{
my($self) = @_;
if (exists $obj2id{$self})
{
warn "Object '$self' has already been registered!\n";
return $obj2id{$self};
}
else
{
$id2obj{$ID} = $self;
$obj2id{$self} = $ID;
return $ID++;
}
}
sub ID2Obj
{
my($self,$id) = @_;
return exists($id2obj{$id}) ? $id2obj{$id} : undef;
}
sub Obj2ID
{
my($self) = @_;
return exists($obj2id{$self}) ? $obj2id{$self} : undef;
}
sub Registered
{
return $ID;
}
package main;
use strict;
use Date::Calc::Object;
use Bit::Vector::Overload;
push( @Date::Calc::ISA, 'InheritMe' ); # (make Date::Calc a subclass)
InheritMe->import(':all'); # (as a convenience for dealing with non-objects)
Date::Calc->date_format(2);
my $today = Date::Calc->today();
my $yesterday = $today - 1;
my $tomorrow = $today + 1;
print "\nDates:\n";
print "'$yesterday' has got ID #", $yesterday->RegisterMe(), "\n";
print "'$today' has got ID #", $today->RegisterMe(), "\n";
print "'$tomorrow' has got ID #", $tomorrow->RegisterMe(), "\n";
my $pears = 50;
my $apples = 1;
my $oranges = 'out of stock';
print "\nFruit:\n";
print "\$pears ('$pears') has got ID #", RegisterMe(\$pears), "\n";
print "\$apples ('$apples') has got ID #", RegisterMe(\$apples), "\n";
print "\$oranges ('$oranges') has got ID #", RegisterMe(\$oranges), "\n";
my $set1 = Bit::Vector->new(&Registered);
my $set2 = Bit::Vector->new(&Registered);
$set1->Bit_On( $today->Obj2ID() );
$set1->Bit_On( Obj2ID(\$pears) );
$set1->Bit_On( Obj2ID(\$apples) );
$set1->Bit_On( Obj2ID(\$oranges) );
$set2->Bit_On( $yesterday->Obj2ID() );
$set2->Bit_On( $today->Obj2ID() );
$set2->Bit_On( $tomorrow->Obj2ID() );
$set2->Bit_On( Obj2ID(\$oranges) );
print "\nSet #1:\n";
print "<",
join
(
'> <',
map
(
ref($_) =~ /^[A-Z]+$/ ? "${$_}" : "$_",
map
(
InheritMe->ID2Obj($_),
$set1->Index_List_Read()
)
)
),
">\n";
print "\nSet #2:\n";
print "<",
join
(
'> <',
map
(
ref($_) =~ /^[A-Z]+$/ ? "${$_}" : "$_",
map
(
InheritMe->ID2Obj($_),
$set2->Index_List_Read()
)
)
),
">\n";
my $intersection = $set1 & $set2;
print "\nIntersection:\n";
print "<",
join
(
'> <',
map
(
ref($_) =~ /^[A-Z]+$/ ? "${$_}" : "$_",
map
(
InheritMe->ID2Obj($_),
$intersection->Index_List_Read()
)
)
),
">\n";
__END__
|
