NAME

Class::NonOO - Use methods as functions with an implicit singleton

SYNOPSYS

In a module:

  package MyModule;

  use Class::NonOO;

  ...

  sub my_method {
     my ($self, @args) = @_;
     ...
  }

  as_function
    export => [ 'my_method' ], # methods to export
    args   => [ ];             # constructor args

The module can be be used with a function calling style:

  use MyModule;

  ...

  my_method(@args);

DESCRIPTION

This module allows you to turn a class into a module that exports methods as functions that use an implicit singleton. This allows you to provide a "hybrid" object-oriented/functional interface.

EXPORTS

as_function

  as_function
    export      => [ ... ], # @EXPORT
    export_ok   => [ ... ], # @EXPORT_OK (optional)
    export_tags => { ... }, # %EXPORT_TAGS (optional)
    args        => [ ... ], # constructor args (optional)
    global      => 0;       # no global state (default)

This wraps methods in a function that checks the first argument. If the argument is an instance of the class, then it assumes it is a normal method call. Otherwise it assumes it is a function call, and it calls the method with the singleton instance.

If the export option is omitted, it will default to the contents of the @EXPORT variable. The same holds for the export_ok and export_tags options and the @EXPORT_OK and %EXPORT_TAGS variables, respectively.

Note that this will not work properly on methods that take an instance of the class as the first argument.

By default, there is no global state. That means that there is a different implicit singleton for each namespace. This offers some protection when the state is changed in one module, so that it does not affect the state in another module.

If you want to enable global state, you can set global to a true value. This is not recommended for CPAN modules.

You might work around this by using something like

  local %MyClass::_DEFAULT_SINGLETONS;

but this is not recommended. If you need to modify state and share it across modules, you should be passing around individual objects instead of singletons.

SEE ALSO

Class::Exporter is a similar module.

AUTHOR

Robert Rothenberg, <rrwo at cpan.org>

LICENSE AND COPYRIGHT

Copyright 2015-2016 Robert Rothenberg.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

cpanm Class::NonOO

perl -MCPAN -e shell
install Class::NonOO