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
|
package parent;
use strict;
use vars qw($VERSION);
$VERSION = '0.236';
sub import {
my $class = shift;
my $inheritor = caller(0);
if ( @_ and $_[0] eq '-norequire' ) {
shift @_;
} else {
for ( my @filename = @_ ) {
s{::|'}{/}g;
require "$_.pm"; # dies if the file is not found
}
}
{
no strict 'refs';
push @{"$inheritor\::ISA"}, @_; # dies if a loop is detected
};
};
1;
__END__
=encoding utf8
=head1 NAME
parent - Establish an ISA relationship with base classes at compile time
=head1 SYNOPSIS
package Baz;
use parent qw(Foo Bar);
=head1 DESCRIPTION
Allows you to both load one or more modules, while setting up inheritance from
those modules at the same time. Mostly similar in effect to
package Baz;
BEGIN {
require Foo;
require Bar;
push @ISA, qw(Foo Bar);
}
By default, every base class needs to live in a file of its own.
If you want to have a subclass and its parent class in the same file, you
can tell C<parent> not to load any modules by using the C<-norequire> switch:
package Foo;
sub exclaim { "I CAN HAS PERL" }
package DoesNotLoadFooBar;
use parent -norequire, 'Foo', 'Bar';
# will not go looking for Foo.pm or Bar.pm
This is equivalent to the following code:
package Foo;
sub exclaim { "I CAN HAS PERL" }
package DoesNotLoadFooBar;
push @DoesNotLoadFooBar::ISA, 'Foo', 'Bar';
This is also helpful for the case where a package lives within
a differently named file:
package MyHash;
use Tie::Hash;
use parent -norequire, 'Tie::StdHash';
This is equivalent to the following code:
package MyHash;
require Tie::Hash;
push @ISA, 'Tie::StdHash';
If you want to load a subclass from a file that C<require> would
not consider an eligible filename (that is, it does not end in
either C<.pm> or C<.pmc>), use the following code:
package MySecondPlugin;
require './plugins/custom.plugin'; # contains Plugin::Custom
use parent -norequire, 'Plugin::Custom';
=head1 HISTORY
This module was forked from L<base> to remove the cruft
that had accumulated in it.
=head1 CAVEATS
=head1 SEE ALSO
L<base>
=head1 AUTHORS AND CONTRIBUTORS
Rafaël Garcia-Suarez, Bart Lateur, Max Maischein, Anno Siegel, Michael Schwern
=head1 MAINTAINER
Max Maischein C< corion@cpan.org >
Copyright (c) 2007-10 Max Maischein C<< <corion@cpan.org> >>
Based on the idea of C<base.pm>, which was introduced with Perl 5.004_04.
=head1 LICENSE
This module is released under the same terms as Perl itself.
=cut
|
