Programming Perl, 4th Edition

parent

use parent qw(Mother Father);

The parent pragma supersedes the base pragma. It loads modules and sets up inheritance relationships without the %FIELDS hash magic, and it provides a way to set up inheritance without loading files.

The following example is equivalent to loading both parent modules and adding them to @INC without declaring @INC explicitly:

BEGIN {
    require Mother;
    require Father;
    push @ISA, qw(Mother Father);
}

This assumes each parent module lives in its own file. If the parent classes do not live in separate files, perhaps because you’ve defined them in the same file or already loaded them from a file as part of another class, you can use the –norequire option to merely set up the inheritance relationship:

use parent qw(–norequire Mother Father);

This is equivalent to adding those classes to @ISA:

BEGIN {
    push @ISA, qw(Mother Father);
}