NAME

    Role::Tiny - Roles. Like a nouvelle cuisine portion size slice of Moose.

SYNOPSIS

     package Some::Role;

     use Role::Tiny;

     sub foo { ... }

     sub bar { ... }

     around baz => sub { ... };

     1;

    elsewhere

     package Some::Class;

     use Role::Tiny::With;

     # bar gets imported, but not foo

     with 'Some::Role';

     sub foo { ... }

     # baz is wrapped in the around modifier by Class::Method::Modifiers

     sub baz { ... }

     1;

    If you wanted attributes as well, look at Moo::Role.

DESCRIPTION

    "Role::Tiny" is a minimalist role composition tool.

ROLE COMPOSITION

    Role composition can be thought of as much more clever and meaningful

    multiple inheritance. The basics of this implementation of roles is:

    * If a method is already defined on a class, that method will not be

      composed in from the role. A method inherited by a class gets

      overridden by the role's method of the same name, though.

    * If a method that the role "requires" to be implemented is not

      implemented, role application will fail loudly.

    Unlike Class::C3, where the last class inherited from "wins," role

    composition is the other way around, where the class wins. If multiple

    roles are applied in a single call (single with statement), then if any

    of their provided methods clash, an exception is raised unless the class

    provides a method since this conflict indicates a potential problem.

IMPORTED SUBROUTINES

  requires

     requires qw(foo bar);

    Declares a list of methods that must be defined to compose role.

  with

     with 'Some::Role1';

     with 'Some::Role1', 'Some::Role2';

    Composes another role into the current role (or class via

    Role::Tiny::With).

    If you have conflicts and want to resolve them in favour of Some::Role1

    you can instead write:

     with 'Some::Role1';

     with 'Some::Role2';

    If you have conflicts and want to resolve different conflicts in favour

    of different roles, please refactor your codebase.

  before

     before foo => sub { ... };

    See "before method(s) => sub { ... }" in Class::Method::Modifiers for

    full documentation.

    Note that since you are not required to use method modifiers,

    Class::Method::Modifiers is lazily loaded and we do not declare it as a

    dependency. If your Role::Tiny role uses modifiers you must depend on

    both Class::Method::Modifiers and Role::Tiny.

  around

     around foo => sub { ... };

    See "around method(s) => sub { ... }" in Class::Method::Modifiers for

    full documentation.

    Note that since you are not required to use method modifiers,

    Class::Method::Modifiers is lazily loaded and we do not declare it as a

    dependency. If your Role::Tiny role uses modifiers you must depend on

    both Class::Method::Modifiers and Role::Tiny.

  after

     after foo => sub { ... };

    See "after method(s) => sub { ... }" in Class::Method::Modifiers for

    full documentation.

    Note that since you are not required to use method modifiers,

    Class::Method::Modifiers is lazily loaded and we do not declare it as a

    dependency. If your Role::Tiny role uses modifiers you must depend on

    both Class::Method::Modifiers and Role::Tiny.

  Strict and Warnings

    In addition to importing subroutines, using "Role::Tiny" applies strict

    and warnings to the caller.

SUBROUTINES

  does_role

     if (Role::Tiny::does_role($foo, 'Some::Role')) {

       ...

     }

    Returns true if class has been composed with role.

    This subroutine is also installed as ->does on any class a Role::Tiny is

    composed into unless that class already has an ->does method, so

      if ($foo->does('Some::Role')) {

        ...

      }

    will work for classes but to test a role, one must use ::does_role

    directly.

    Additionally, Role::Tiny will override the standard Perl "DOES" method

    for your class. However, if "any" class in your class' inheritance

    hierarchy provides "DOES", then Role::Tiny will not override it.

METHODS

  apply_roles_to_package

     Role::Tiny->apply_roles_to_package(

       'Some::Package', 'Some::Role', 'Some::Other::Role'

     );

    Composes role with package. See also Role::Tiny::With.

  apply_roles_to_object

     Role::Tiny->apply_roles_to_object($foo, qw(Some::Role1 Some::Role2));

    Composes roles in order into object directly. Object is reblessed into

    the resulting class. Note that the object's methods get overridden by

    the role's ones with the same names.

  create_class_with_roles

     Role::Tiny->create_class_with_roles('Some::Base', qw(Some::Role1 Some::Role2));

    Creates a new class based on base, with the roles composed into it in

    order. New class is returned.

  is_role

     Role::Tiny->is_role('Some::Role1')

    Returns true if the given package is a role.

CAVEATS

    *   On perl 5.8.8 and earlier, applying a role to an object won't apply

        any overloads from the role to other copies of the object.

    *   On perl 5.16 and earlier, applying a role to a class won't apply any

        overloads from the role to any existing instances of the class.

SEE ALSO

    Role::Tiny is the attribute-less subset of Moo::Role; Moo::Role is a

    meta-protocol-less subset of the king of role systems, Moose::Role.

    Ovid's Role::Basic provides roles with a similar scope, but without

    method modifiers, and having some extra usage restrictions.

AUTHOR

    mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>

CONTRIBUTORS

    dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>

    frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>

    hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>

    jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>

    ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>

    chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>

    ajgb - Alex J. G. Burzyński (cpan:AJGB) <ajgb@cpan.org>

    doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>

    perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>

    Mithaldu - Christian Walde (cpan:MITHALDU)

    <walde.christian@googlemail.com>

    ilmari - Dagfinn Ilmari Mannsåker (cpan:ILMARI) <ilmari@ilmari.org>

    tobyink - Toby Inkster (cpan:TOBYINK) <tobyink@cpan.org>

    haarg - Graham Knop (cpan:HAARG) <haarg@haarg.org>

COPYRIGHT

    Copyright (c) 2010-2012 the Role::Tiny "AUTHOR" and "CONTRIBUTORS" as

    listed above.

LICENSE

    This library is free software and may be distributed under the same

    terms as perl itself.