NAME
    Gloom - Gloom (the Great Little OO Module)

SYNOPSIS
    In your "Makefile.PL":

        use inc::Module::Install;
        name 'MyMod';
        use_gloom 'MyMod::OO';

    then in "lib/MyMod/Foo.pm":

        package MyMod::Foo;
        use MyMod::OO -base;

        has 'foo';

    and:

        package MyMod::Foo::Bar;
        use MyMod::Foo -base;

        has 'bar';

NOTE
    Module::Install is not required to use Gloom. It just makes it a trivial
    process. If you don't use Module::Install, you can manually copy/symlink
    Gloom.pm to your "lib/MyMod/OO.pm".

DESCRIPTION
    Gloom is a simple, clean and small OO base module. It can be used by
    CPAN modules that need to be OO, but don't want to require a dependency
    module to do it.

    Gloom provides the OO basics like single inheritance, standard "new" and
    "init" constructor methods, and "has" attribute accessors. It also turns
    on "strict" and "warnings" automatically.

    Gloom is cascading. Using Gloom as a base class for class "Foo", enables
    "Foo" to later be used as a Gloomy base class. Using the "-base" syntax
    invokes all the Gloom functionality.

WHENCE GLOOM?
    Using basic idiomatic OO in Perl is problematic. Perl provides the
    lowest level mechanisms, but this is not even the bare minimum that you
    would find useable. You'd want at least an object constructor and
    attribute accessors.

    Moose and friends is the way to do serious OO right, but Moose has
    issues too. Imagine you want to write a very simple CPAN module, and
    want to do it in the OO style. Adding a Moose prerequisite feels like
    adding an army tank to a flower arrangement. It's a huge installation
    pain for your users if its not already installed, and it still carries a
    startup performance penalty.

    This is where Gloom comes in. Gloom is a CPAN module author's friend. It
    provides Perl OO basics with No Dependency Prerequisites. You simply
    copy or symlink "Gloom.pm" as your module's OO base module, then Gloom
    will figure out the rest.

    The great lesson of "Module::Install" is that you can fix deficiencies
    in standard things like ExtUtils::MakeMaker or even "perl" itself, by
    shipping a little extra code with each module. With Gloom, you always
    ship Gloom.pm, renamed as your OO base module.

    If you use Module::Install, all you need to do is add a line to your
    "Makefile.PL" file. It will create a Gloom based OO module for you and
    keep it up to date. Just imagine, all your Perl OO needs resolved with
    one line in a Makefile.PL! See Module::Install::Gloom for details.

    The great lesson of Spiffy was OO feature propagation/cascading. When a
    module is a Gloom subclass, it can be used as a first-rate Gloom base
    class.

    Spiffy was not well received by some people because it used source
    filtering for a couple unrelated things. Just for the record, Gloom uses
    no source filtering or any other fancy magics.

    Gloom has nothing except the OO primitives that everyone wants. Gloom
    simply makes basic Perl OO something that you don't need to worry about
    any more.

FEATURES
    Gloom provides the following features:

    Usage, Inheritance and Cascading
        When you use a Gloom subclass module, you can pass it the "-base"
        option to establish single inheritance to that module. In other
        words, that module becomes your module's base or parent class.

            package My::Foo;
            use My::OO -base;

        Now you are free to use My::Foo as a base class for some other
        class:

            package Your::Foo;
            use My::Foo -base;

            has 'what_you_want';

        My::Foo has all the exact same powers of OO cascading as Gloom
        itself.

        Note that My::OO is an exact copy of Gloom.pm. You don't change
        anything in the file. The code sees how it was called and adapts the
        package name on the fly.

    Constructor
        Gloom has a "new()" class method. It creates an object and calls
        "$self- >init(@_)".

        The default "init()" method expects its arguments to be a list of
        attribute name/value pairs. You can easily subclass "init()" to do
        things differently.

    Attribute Accessor Generators
        Gloom provides "has" accessors that work exactly like the "field"
        accessors from "Class::Field". ("has" is the Perl standard name for
        attribute generators). The attributes are always read/write. They
        provide an optional default value as well as an optional
        initialization code snippet.

            package Foo;
            use Bar -base;

            has 'this';
            has 'that' => {};    # Defaults to a hash;
            has 'thus', -init => '$self->set_thus';

        You can also mark them to support method chaining:

            has 'this', -chain;
            has 'that';

            $self->this('one')->that('two');

        NOTE: Gloom "has()" is completely different in usage from Moose
        "has()".

    Exporting
        Gloom and all its subclasses export the "has()" function. You can
        have your base class export more things by simply defining the
        Exporter variables, like:

            our @EXPORT = qw(foo bar);
            our @EXPORT_OK = qw(baz);

    Other Stuff
        Since the "has" generators always return a true value, you usually
        don't need the annoying:

            1;

        line at the bottom of your Gloom based modules. The true value they
        return is the Perl source code of the accessor. You can see this by
        doing something like:

            print has 'foo' -init => '$self->init_foo';

        Like Moose, using Gloom (or any subclass of Gloom) as a base class,
        will automagically do the equivalent of:

            use strict;
            use warnings;

REPOSITORY AND COMMUNITY
    The Gloom module can be found on CPAN and on GitHub:
    "/github.com/ingydotnet/gloom- pm" in http:.

    Please join #gloom on irc.perl.org to discuss the new Gloom of Perl.

AUTHOR
    ingy döt Net <ingy@cpan.org>

COPYRIGHT
    Copyright 2010-2014. Ingy döt Net.

    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>

