1parent(3) User Contributed Perl Documentation parent(3)
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6 parent - Establish an ISA relationship with base classes at compile
7 time
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10 package Baz;
11 use parent qw(Foo Bar);
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14 Allows you to both load one or more modules, while setting up
15 inheritance from those modules at the same time. Mostly similar in
16 effect to
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18 package Baz;
19 BEGIN {
20 require Foo;
21 require Bar;
22 push @ISA, qw(Foo Bar);
23 }
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25 By default, every base class needs to live in a file of its own. If
26 you want to have a subclass and its parent class in the same file, you
27 can tell "parent" not to load any modules by using the "-norequire"
28 switch:
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30 package Foo;
31 sub exclaim { "I CAN HAS PERL" }
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33 package DoesNotLoadFooBar;
34 use parent -norequire, 'Foo', 'Bar';
35 # will not go looking for Foo.pm or Bar.pm
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37 This is equivalent to the following code:
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39 package Foo;
40 sub exclaim { "I CAN HAS PERL" }
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42 package DoesNotLoadFooBar;
43 push @DoesNotLoadFooBar::ISA, 'Foo', 'Bar';
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45 This is also helpful for the case where a package lives within a
46 differently named file:
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48 package MyHash;
49 use Tie::Hash;
50 use parent -norequire, 'Tie::StdHash';
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52 This is equivalent to the following code:
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54 package MyHash;
55 require Tie::Hash;
56 push @ISA, 'Tie::StdHash';
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58 If you want to load a subclass from a file that "require" would not
59 consider an eligible filename (that is, it does not end in either ".pm"
60 or ".pmc"), use the following code:
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62 package MySecondPlugin;
63 require './plugins/custom.plugin'; # contains Plugin::Custom
64 use parent -norequire, 'Plugin::Custom';
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67 Class 'Foo' tried to inherit from itself
68 Attempting to inherit from yourself generates a warning.
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70 package Foo;
71 use parent 'Foo';
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74 This module was forked from base to remove the cruft that had
75 accumulated in it.
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79 base
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82 Rafaeel Garcia-Suarez, Bart Lateur, Max Maischein, Anno Siegel, Michael
83 Schwern
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86 Max Maischein " corion@cpan.org "
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88 Copyright (c) 2007-10 Max Maischein "<corion@cpan.org>" Based on the
89 idea of "base.pm", which was introduced with Perl 5.004_04.
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92 This module is released under the same terms as Perl itself.
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96perl v5.16.3 2011-03-08 parent(3)