Package::Transporter::Generator::Potential::Export - On-demand (proxy) export

	use strict;

	package Synopsis;
	use Package::Transporter sub{eval shift}, sub {
		$_[0]->register_potential('::Export', 'FOR_BRANCH',
			['hello_world', 'yn']);
	};

	sub hello_world() { print "Hello World.\n"; };
	sub yn() { print STDERR ($_[0] ? 'Yes' : 'No'), "\n"; };

	


	package Synopsis::Ex1;
	use Package::Transporter sub{eval shift};

	yn(!defined(&hello_world));
	yn(potentially_defined('hello_world'));

	hello_world();

	yn(defined(&hello_world));
	exit(0);

Takes the requested subroutine from the given package name of the defining package, if no explicit package name is given.

'FOR_SELF' wildcard makes only sense while acting as a proxy.

Set this package global to allow the generator to eventually trigger other generators. Nothing wrong with that, it just exists to highlight what to look for when writing generators.

$Package::Transporter::Generator::Potential::Closures_Demo::ONLY_DEFINED_ORIGINALS = 0;

An package name from where to take the subroutines from can be specified as follows.

	use strict;

	package Synopsis;
	use Package::Transporter sub{eval shift}, sub {
		my $generator = $_[0]->create_generator('::Export', 
			'POSIX', 'Data::Dumper');
		$_[0]->register_potential($generator, 'FOR_SELF');
	};

	sub yn($) { print STDERR ($_[0] ? 'Yes' : 'No'), "\n"; };

	yn(!defined(&O_EXCL));
	yn(potentially_defined('O_EXCL'));

	print STDERR O_EXCL(), "\n"; # now points to POSIX::O_EXCL()

	yn(defined(&O_EXCL));
	exit(0);

Note that the Export generator will do an 'require POSIX' and will (in absense of an explicit name definition) install a subroutine name matcher to check with what is available in the POSIX module.

Prototype definitions are not supported. Although the rule could see which subroutines are for export in the defining package, get their prototype definition with prototype() and submit a prototype to each requesting package. This is unlikely to be implemented unless prototypes are honored for AUTOLOADed subroutines.

Please see the documentation of the upstream package Package::Transporter.