NAME
    AutoRole - Compiletime OR runtime mixin of
    traits/roles/mixins/your-word-here.

    $Id: AutoRole.pm,v 1.7 2010-07-14 13:25:31 paul Exp $

SYNOPSIS
      use AutoRole Bam => [qw(bar baz bim)];

      use AutoRole
        class   => 'Bam',
        how     => 'autorequire',
        methods => [qw(bar baz bim)];

      use AutoRole
        class   => 'Bam',
        how     => 'compile',
        methods => {
           bar => 1,
           baz => 1,
           bim => 'bim_by_some_other_name',
        };

      use AutoRole
        class   => 'Bam',
        how     => $ENV{'MOD_PERL'} && 'compile', # will default to autorequire if not mod_perl
        method  => 'flimflam',

      use AutoRole
        class   => 'Bam',
        how     => 'autoload', # better if you are using many many mixin methods
        methods => [qw(bar baz bim biz boon bong brim)];

      use AutoRole Bam => [qw(bar baz bim)];
      use AutoRole Bam => autorequire => [qw(bar baz bim)]; # same thing
      use AutoRole Bam => compile     => [qw(bar baz bim)];

      use AutoRole Bam => methods => '*';      # load ALL methods from Bam - at compile time
      use AutoRole Bam => '*';                 # same thing
      use AutoRole 'Bam';                      # same thing
      use AutoRole Bam => {'*' => qr{^bam_}};  # load All methods from Bam that begin with bam_
      use AutoRole Bam => qr{^bam_};           # same thing

      use AutoRole Bam => qr{^(?!bam_)};       # load ALL methods not beginning with bam_

DESCRIPTION
    AutoRole is similar to many of the CPAN variants that handle things
    refered to as Traits, Roles, and Mixins. All of these are fairly similar
    to each other (in Perl land) though there are subtle nuances. If you use
    the type "how" of compile - there is little difference in using AutoRole
    vs. the CPAN counterparts.

    If you use autorequire or autoload however, you save loading the modules
    until it is necessary to do so. This allows for the creation of "heavy"
    interfaces with very light frontends. AutoRole allows for only loading
    extra modules if that role's interface is used.

    One more win with roles/mixins/traits is that you can keep your
    inheritance tree sane (rather than inheriting from a role class).

PARAMETERS
    In many cases the class, how, and method keywords are not needed and the
    intent can be determined based on the types of parameters. However, you
    can always pass the parameter names to be specific.

    "class"
        This represents the class you would like to load the roles from.

    "how"
        Can be one of compile, autorequire, or autoload. Default is
        autorequire if methods are passed, default is compile if no methods
        are passed or if '*' or qr{} are used for methods.

        Option "compile" will load the module and mix the specified
        subs/methods in as needed at compile time.

        Option "autorequire" does not load the module at compile time,
        instead it loads a stub subroutine that will require the module,
        re-install the real subroutine in place of the stub, and then goto
        that subroutine (to keep the call stack like it should be).

        Option "autoload" tries to do as little work as possible by only
        installing an AUTOLOAD subroutine that will load the role methods
        when called. This is a good option over autorequire if you have a
        large number of role methods (it gives more of a runtime hit rather
        than a compiletime hit).

    "methods" or "method"
        Takes an arrayref or hashref of names or a single method name to
        load. If a hashref is passed, the value may be a different name to
        alias it to, or an arrayref of names to alias to.

            method => 'foo'

            methods => 'foo'

            methods => ['foo'],

            methods => {foo => 1},

            methods => {foo => 'foo'}

            methods => {foo => 'bar'}           # installs a method called bar rather than foo
            methods => {foo => ['bar', 'baz']}  # installs both bar and baz as rather than foo

        You can use the special method name of "*" to load all of the
        methods from the sub. The downside to this is it will automatically
        change to compile time behavior (because it needs to lookup the list
        of available methods).

            method => '*'

            method => {'*' => 1},

        If the methods are specified with a hashref, the value of a "*"
        entry may be a regex that will be used to match method names. Note
        however that this retrieval is only one class deep - so if your role
        inherits from a base role you will need to load it separately.

            method => {'*' => qr{^debug}} # loads all methods beginning with debug

            methods => {foo => 1,
                        '*' => qr{^bar},  # loads foo and any other method beginning with bar
                       }

        If you use "*" and other aliases at the same time, the other aliases
        win.

        Since it is a common thing to do - you may also pass simply a qr{}
        and it will work like {'*' => qr{}}.

            methods => qr{^debug}     # load all methods beginning with debug

            methods => qr{^(?!debug)} # load all methods not beginning with debug

        If the how option is "compile" and no method or methods are passed,
        it will default to '*'. However if no methods are passed on
        autorequire or autoload, it will die.

DIAGNOTICS
    "Missing class name"
        Occurs when the "class" paramter name is used but no class name
        follows.

    "Missing how type"
        Occurs when the "how" type is used but no type follows.

    "How type $how is invalid"
        Type can only be compile or autorequire.

    "Method name conflict - ${pkg}::$dest already exists"
        Occurs if you try and use a method name from a role that is already
        defined as a method in your class. You can work around this by using
        the alias feature of the "method" parameter.

    "Missing list of methods to load"
        Occurs if you fail to pass a list of methods during autorequire or
        autoload. Note that if you don't pass a list under how type
        "compile" it will default to '*'.

AUTHOR
    Paul Seamons

LICENSE
    This module may be distributed under the same terms as Perl itself.

