package parent; use strict; use vars qw($VERSION); $VERSION = '0.221'; sub import { my $class = shift; my $inheritor = caller(0); if ( @_ and $_[0] eq '-norequire' ) { shift @_; } else { for ( my @filename = @_ ) { if ( $_ eq $inheritor ) { warn "Class '$inheritor' tried to inherit from itself\n"; }; s{::|'}{/}g; require "$_.pm"; # dies if the file is not found } } { no strict 'refs'; # This is more efficient than push for the new MRO # at least until the new MRO is fixed @{"$inheritor\::ISA"} = (@{"$inheritor\::ISA"} , @_); }; }; "All your base are belong to us" __END__ =head1 NAME parent - Establish an ISA relationship with base classes at compile time =head1 SYNOPSIS package Baz; use parent qw(Foo Bar); =head1 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 C not to load any modules by using the C<-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'; 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 C would not consider an eligible filename (that is, it does not end in either C<.pm> or C<.pmc>), use the following code: package MySecondPlugin; require './plugins/custom.plugin'; # contains Plugin::Custom use parent -norequire, 'Plugin::Custom'; =head1 DIAGNOSTICS =over 4 =item Class 'Foo' tried to inherit from itself Attempting to inherit from yourself generates a warning. use Foo; use parent 'Foo'; =back =head1 HISTORY This module was forked from L to remove the cruft that had accumulated in it. =head1 CAVEATS =head1 SEE ALSO L =head1 AUTHORS AND CONTRIBUTORS Rafaël Garcia-Suarez, Bart Lateur, Max Maischein, Anno Siegel, Michael Schwern =head1 MAINTAINER Max Maischein C< corion@cpan.org > Copyright (c) 2007 Max Maischein C<< >> Based on the idea of C, which was introduced with Perl 5.004_04. =head1 LICENSE This module is released under the same terms as Perl itself. =cut