NAME

namespace::functions - Keep package's namespace clean

SYNOPSIS

  package My::Class;

  # import some function
  use Scalar::Util 'looks_like_number';

  # collect the names of all previously created functions
  use namespace::functions;

  # our function uses imported function
  sub is_num {
      my ($self, $val) = @_;
      return looks_like_number("$val");
  }

  # delete all previously collected functions
  no namespace::functions;

  # our package doesn't provide imported function anymore!

DESCRIPTION

This pragma allows to collect all functions existing in package's namespace and finally delete them.

The problem is that any function which is imported to your package, stays a part of public API of this package. I.e.:

  package My::PollutedClass;
  use Scalar::Util 'looks_like_number';

  sub is_num {
      my ($val) = @_;
      return looks_like_number("$val");
  }

  package main;
  print My::PollutedClass->can('looks_like_number');  # true

Deleting imported function from package's stash is a solution, because the function will be not available at run-time:

  delete {\%My::PoorSolutionClass::}->{looks_like_number};

The namespace::functions collects the function names and finally deletes them from package's namespace.

IMPORTS

use namespace::functions;

Collects all functions from our namespace.

use namespace::functions -except => 'func';
use namespace::functions -except => ['func1', 'func2'];

Collects all functions from our namespace without listed functions.

no namespace::functions;

Deletes all previously collected functions from our namespace.

use namespace::functions -also => 'func';
use namespace::functions -also => ['func1', 'func2'];

Deletes all previously collected functions and also additional functions from our namespace.

OVERVIEW

This pragma needs to be placed in the right order: after last use which imports some unwanted functions and before first sub.

  package My::Example;

  use Carp 'confess';
  use Scalar::Util 'blessed'

  use namespace::functions;

  sub some_method {
      my ($self) = @_;
      confess("Call as a method") if not blessed($self);
      # ...
  };

  no namespace::functions;

You can check if your package is clean with Class::Inspector module and its methods: functions and methods.

  use My::Example;
  use Class::Inspector;
  use YAML;
  print Dump ( {
        functions => [Class::Inspector->functions("My::Example")],
        methods   => [Class::Inspector->methods("My::Example")],
  } );

Moose

Moose keywords can be unexported with no Moose statement. Even that, Moose imports following functions: blessed, confess, meta. The meta method is required by Moose framework and should be unchanged. The others can be deleted safely.

  package My::MooseClass;

  use Moose;

  use namespace::functions -except => 'meta';

  sub my_method {
      my ($self, $arg) = @_;
      return blessed $self;
  };

  no namespace::functions;

  # The My::MooseClass now provides "my_method" and "meta" only.

SEE ALSO

This module is inspired by namespace::clean module but it doesn't require compiled XS modules. It also doesn't work lexically so unimport method have to be called explicitly.

See also: namespace::clean, Class::Inspector.

BUGS

If you find the bug or want to implement new features, please report it at http://rt.cpan.org/NoAuth/Bugs.html?Dist=namespace-functions

AUTHOR

Piotr Roszatycki <dexter@cpan.org>

COPYRIGHT

Copyright (C) 2009, 2011 by Piotr Roszatycki <dexter@cpan.org>.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

See http://www.perl.com/perl/misc/Artistic.html