DOKK / manpages / debian 12 / libclass-virtual-perl / Class::Virtually::Abstract.3pm.en
Class::Virtually::Abstract(3pm) User Contributed Perl Documentation Class::Virtually::Abstract(3pm)

Class::Virtually::Abstract - Compile-time enforcement of Class::Virtual

  package My::Virtual::Idaho;
  use base qw(Class::Virtually::Abstract);
  __PACKAGE__->virtual_methods(qw(new foo bar this that));
  package My::Private::Idaho;
  use base qw(My::Virtual::Idaho);
  sub new { ... }
  sub foo { ... }
  sub bar { ... }
  sub this { ... }
  # oops, forgot to implement that()!!  Whatever will happen?!
  # Meanwhile, in another piece of code!
  # KA-BLAM!  My::Private::Idaho fails to compile because it didn't
  # fully implement My::Virtual::Idaho.
  use My::Private::Idaho;

This subclass of Class::Virtual provides compile-time enforcement. That means subclasses of your virtual class are required to implement all virtual methods or else it will not compile.

Because this relies on import() it is important that your classes are used instead of required. This is a problem, and I'm trying to figure a way around it.

Also, if a subclass defines its own import() routine (I've done it) Class::Virtually::Abstract's compile-time checking is defeated.

Got to think of a better way to do this besides import().

Original idea and code from Ben Tilly's AbstractClass http://www.perlmonks.org/index.pl?node_id=44300&lastnode_id=45341

Embraced and Extended by Michael G Schwern <schwern@pobox.com>

Class::Virtual

2022-06-12 perl v5.34.0