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base(3pm) [mojave man page]

base(3pm)						 Perl Programmers Reference Guide						 base(3pm)

NAME
base - Establish an ISA relationship with base classes at compile time SYNOPSIS
package Baz; use base qw(Foo Bar); DESCRIPTION
Unless you are using the "fields" pragma, consider this module discouraged in favor of the lighter-weight "parent". Allows you to both load one or more modules, while setting up inheritance from those modules at the same time. Roughly similar in effect to package Baz; BEGIN { require Foo; require Bar; push @ISA, qw(Foo Bar); } When "base" tries to "require" a module, it will not die if it cannot find the module's file, but will die on any other error. After all this, should your base class be empty, containing no symbols, "base" will die. This is useful for inheriting from classes in the same file as yourself but where the filename does not match the base module name, like so: # in Bar.pm package Foo; sub exclaim { "I can have such a thing?!" } package Bar; use base "Foo"; There is no Foo.pm, but because "Foo" defines a symbol (the "exclaim" subroutine), "base" will not die when the "require" fails to load Foo.pm. "base" will also initialize the fields if one of the base classes has it. Multiple inheritance of fields is NOT supported, if two or more base classes each have inheritable fields the 'base' pragma will croak. See fields for a description of this feature. The base class' "import" method is not called. DIAGNOSTICS
Base class package "%s" is empty. base.pm was unable to require the base package, because it was not found in your path. Class 'Foo' tried to inherit from itself Attempting to inherit from yourself generates a warning. package Foo; use base 'Foo'; HISTORY
This module was introduced with Perl 5.004_04. CAVEATS
Due to the limitations of the implementation, you must use base before you declare any of your own fields. SEE ALSO
fields perl v5.18.2 2014-01-06 base(3pm)

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parent(3pm)						 Perl Programmers Reference Guide					       parent(3pm)

NAME
parent - Establish an ISA relationship with base classes at compile time SYNOPSIS
package Baz; use parent qw(Foo Bar); 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 "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'; DIAGNOSTICS
Class 'Foo' tried to inherit from itself Attempting to inherit from yourself generates a warning. package Foo; use parent 'Foo'; HISTORY
This module was forked from base to remove the cruft that had accumulated in it. CAVEATS
SEE ALSO
base AUTHORS AND CONTRIBUTORS
Rafaeel Garcia-Suarez, Bart Lateur, Max Maischein, Anno Siegel, Michael Schwern MAINTAINER
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. LICENSE
This module is released under the same terms as Perl itself. perl v5.18.2 2014-01-06 parent(3pm)

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