base - Establish an ISA relationship with base classes at compile time
- package Baz;
- use base qw(Foo Bar);
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
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.
base.pm was unable to require the base package, because it was not found in your path.
Attempting to inherit from yourself generates a warning.
- package Foo;
- use base 'Foo';
This module was introduced with Perl 5.004_04.
Due to the limitations of the implementation, you must use base before you declare any of your own fields.