base(3p) Perl Programmers Reference Guide base(3p)NAMEbase - Establish IS-A relationship with base classes at com-
pile time
SYNOPSIS
package Baz;
use base qw(Foo Bar);
DESCRIPTION
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);
}
If any of the listed modules are not loaded yet, base
silently attempts to "require" them (and silently continues
if the "require" failed). Whether to "require" a base class
module is determined by the absence of a global variable
$VERSION in the base package. If $VERSION is not detected
even after loading it, <base> will define $VERSION in the
base package, setting it to the string "-1, set by base.pm".
Will also initialize the fields if one of the base classes
has it. Multiple inheritence of fields is NOT supported, if
two or more base classes each have inheritable fields the
'base' pragma will croak. See fields, public and protected
for a description of this feature.
DIAGNOSTICS
Base class package "%s" is empty.
base.pm was unable to require the base package, because
it was not found in your path.
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 v5.8.8 2005-02-05 1
