MooseX...ngleton(3pm)

💅 MooseX::Singleton — turn your Moose class into a singleton, bestie ✨

okay so first things first: this is MooseX::Singleton, version 0.30, and it lives in the Perl world (user-contributed docs, iykyk). slay.

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🌸 NAME 🌸

MooseX::Singleton — literally turns your Moose class into a singleton. no cap.

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🎀 VERSION 🎀

version 0.30 — that's the vibe check and she passed.

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✨ SYNOPSIS ✨

okay so here's the whole mood, copied exactly because code is sacred:

package MyApp;
use MooseX::Singleton;

has env => (
    is      => 'rw',
    isa     => 'HashRef[Str]',
    default => sub { \%ENV },
);

package main;

delete MyApp->env->{PATH};
my $instance = MyApp->instance;
my $same = MyApp->instance;

see how $instance and $same are the same object? that's the whole point, bestie. one instance, main character energy, periodt. 💅

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🦋 DESCRIPTION 🦋

so a singleton is a class that has only one instance in an application — like there can only be one of her, and honestly? she ate.

MooseX::Singleton lets you easily upgrade (or downgrade, as it were 😭) your Moose class to a singleton. the way that you don't even have to do much:

all you should need to do to transform your class is to change use Moose to use MooseX::Singleton. that's it. that's the whole transformation. iconic.

and because this module uses metaclass roles to do its magic, it should cooperate with most other MooseX modules — so no drama, she plays nice with the group chat. 🫶

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💖 METHODS 💖

a singleton class will have the following additional methods (bestie got some new tricks, obsessed):

💜 Singleton->instance

this returns the singleton instance for the given package. it does not accept any arguments — don't come at her with args, she's not about that life.

if the instance does not yet exist, it is created with its default values. but plot twist 🫢: this means that if your singleton requires arguments, calling instance will die if the object has not already been initialized. so like… initialize her first, or she will literally perish.

💜 Singleton->initialize(%args)

this method can be called only once per class — one shot, one opportunity, no do-overs. it explicitly initializes the singleton object with the given arguments. use it wisely, queen. 👑

💜 Singleton->_clear_instance

this clears the existing singleton instance for the class. and obviously, this is meant for use only inside the class itself — it's private, it's giving lore, don't touch it from the outside, k? 🙈

💜 Singleton->new

this method currently works like a hybrid of initialize and instance — a little bit of both, a collab, if you will. ✨

⚠️ but heads up: calling new directly will probably be deprecated in a future release. so instead, call initialize or instance as appropriate. future-proof your code, bestie, it's self-care. 💅

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🌈 SOME CODE STOLEN FROM 🌈

Anders Nor Berle <debolaz@gmail.com> — shoutout, we love a contributor. 🫶

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🌸 AND PATCHES FROM 🌸

Ricardo SIGNES <rjbs@cpan.org> — king behavior, no cap. 👑

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🍓 SUPPORT 🍓

bugs may be submitted through the RT bug tracker at <https://rt.cpan.org/Public/Dist/Display.html?Name=MooseX-Singleton> — or you can email bug-MooseX-Singleton@rt.cpan.org at <mailto:bug-MooseX-Singleton@rt.cpan.org>. iykyk. 🐛

there's also a mailing list available for users of this distribution, at <http://lists.perl.org/list/moose.html> — come hang, bestie.

and there's also an irc channel available for users of this distribution, at "#moose" on "irc.perl.org" at <irc://irc.perl.org/#moose> — the group chat is literally open, pull up. 🌈

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🌟 AUTHOR 🌟

Shawn M Moore <code@sartak.org> — the main character who made this happen. ✨

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🧚 CONTRIBUTORS 🧚

• Dave Rolsky <autarch@urth.org>
• Karen Etheridge <ether@cpan.org>
• Ricardo SIGNES <rjbs@cpan.org>
• Kaare Rasmussen <kaare@jasonic.dk>
• Anders Nor Berle <berle@cpan.org>
• Jonathan Rockway <jon@jrock.us>
• Hans Dieter Pearcey <hdp@weftsoar.net>

the whole squad, the whole team — they all pulled up. 🔥

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💖 COPYRIGHT AND LICENSE 💖

this software is copyright (c) 2007 by Shawn M Moore.

this is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. so like… free, but with rules. read the Perl 5 terms, bestie, they matter. 💅

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and that's the whole page, bestie. you're now a singleton expert, fr fr. go forth and make sure your class only has one of her. 🌈👑

— with love from the docs, perl v5.42.0, dated 2016-11-24 🎀✨