NAME any::feature - Backwards-compatible handling of new syntactic features SYNOPSIS use any::feature 'say'; say 'Hello, world!'; DESCRIPTION THE PROBLEM Perl 5.10 introduces new syntactic features which you can activate and deactivate with the "feature" module. You want to use the "say" feature in a program that's supposed to run under both Perl 5.8 and 5.10. So your program looks like this: use feature 'say'; say 'Hello, world!'; But this only works in Perl 5.10, because there is no "feature" module in Perl 5.8. So you write use Perl6::Say; say 'Hello, world!'; This works, but it's strange to force Perl 5.10 users to install Perl6::Say when the "say" feature is included in Perl 5.10. THE SOLUTION Use "any::feature"! WARNING: This is just a proof-of-concept. "any::feature" can be used like Perl 5.10's "feature" and will try to "do the right thing", regardless of whether you use Perl 5.8 or Perl 5.10. At the moment, this is just a proof-of-concept and only handles the "say" feature. If things work out, I plan to extend it with other Perl 5.10 features. The following programs should work and exhibit the same behaviour both in Perl 5.8 and Perl 5.10. This program will work: use any::feature 'say'; say 'Hello, world!'; This program will fail at compile-time: use any::feature 'say'; say 'Hello, world!'; no any::feature 'say'; say 'Oops'; The features are lexically scoped, which is how they work in Perl 5.10: { use any::feature 'say'; say 'foo'; } say 'bar'; # dies at compile-time SUBROUTINES "dispatch" Takes as arguments a direction ("activate" or "deactivate"), a package name and a feature name. Activates or deactivates the given feature for the given package. "activate" Takes as arguments a package name and a feature name. Uses "dispatch()" to activate the given feature in the given package. "deactivate" Takes as arguments a package name and a feature name. Uses "dispatch()" to deactivate the given feature in the given package. "import" Takes the same arguments as Perl 5.10's "use feature" pragma. Uses "activate()" and "deactivate()" to do its job. "unimport" Takes the same arguments as Perl 5.10's "no feature" pragma. Uses "activate()" and "deactivate()" to do its job. "get_effective_version" Uses Perl::Version to get the version number of the current perl interpreter. This is used to decide the course of action. "get_effective_revision" Uses Perl::Version to get the revision number of the current perl interpreter. This is used to decide the course of action. BUGS AND LIMITATIONS No bugs have been reported. Please report any bugs or feature requests through the web interface at . INSTALLATION See perlmodinstall for information and options on installing Perl modules. AVAILABILITY The latest version of this module is available from the Comprehensive Perl Archive Network (CPAN). Visit to find a CPAN site near you. Or see . The development version lives at . Instead of sending patches, please fork this project using the standard git and github infrastructure. AUTHORS Marcel Grünauer, "" COPYRIGHT AND LICENSE Copyright 2009 by Marcel Grünauer This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.