| parent(3perl) | Perl Programmers Reference Guide | parent(3perl) |
parent - Establish an ISA relationship with base classes at compile time
package Baz;
use parent qw(Foo Bar);
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 "parent" not to load any modules by using the "-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 "require" would not consider an eligible filename (that is, it does not end in either ".pm" or ".pmc"), use the following code:
package MySecondPlugin; require './plugins/custom.plugin'; # contains Plugin::Custom use parent -norequire, 'Plugin::Custom';
This module was forked from base to remove the cruft that had accumulated in it.
base
Rafaël Garcia-Suarez, Bart Lateur, Max Maischein, Anno Siegel, Michael Schwern
Max Maischein " corion@cpan.org "
Copyright (c) 2007-10 Max Maischein "<corion@cpan.org>" Based on the idea of "base.pm", which was introduced with Perl 5.004_04.
This module is released under the same terms as Perl itself.
| 2020-07-21 | perl v5.28.1 |