Object::Lazy(3pm)

📦
version 0.16 · 3 versions
, in ubuntu noble, ubuntu resolute, ubuntu stonking

✨ NAME ✨

Object::Lazy 💖 — creating objects late, from classes that aren't even yours (aka "non-owned" / "foreign" classes). no cap. 🦋

It's a User Contributed Perl Documentation page, it's referenced as Object::Lazy(3pm), and yeah — this is that whole manual, bestie, the entire thing. 🫶

🌈 VERSION 🌈

0.16 ✨ — that's the one.

🎀 SYNOPSIS 🎀

okay so picture this 👑

use Foo 123; # because the class of the real object is Foo, version could be 123
use Object::Lazy;

my $foo = Object::Lazy->new(
    sub {
        return Foo->new;
    },
);

bar($foo);

sub bar {
    my $foo = shift;

    if ($condition) {
        # a foo object will be created
        print $foo->output;
    }
    else {
        # foo object is not created
    }

    return;
}

see the main character energy?? the Foo object literally does not exist until somebody pokes it. and if the else branch happens? it never gets built. periodt. 💅

To combine this and a lazy use, write somthing like that:

use Object::Lazy;

my $foo = Object::Lazy->new(
    sub {
        # 3 lines instead of "use Foo 123"
        require Foo;
        Foo->import;
        Foo->VERSION('123');
        return Foo->new;
    },
);

# and so on

After a build object the scalar which hold the object will be updated too. 🌟

$object->method;
^^^^^^^-------------- will update this scalar after a build

Read topic SUBROUTINES/METHODS to find the entended constructor and all the optional parameters. iykyk 🔥

🍓 EXAMPLE 🍓

Inside of this Distribution is a directory named example. Run this *.pl files. 🧚 that's it, that's the whole thing, go run them bestie!!

🦋 DESCRIPTION 🦋

This module implements lazy evaluation and can create lazy objects from every class. every. single. one. 😭

Creates a dummy object including a subroutine which knows how to build the real object. it's like a placeholder who's secretly a whole architect 🏗️✨

Later, if a method of the object is called, the real object will be built. the glow up is triggered 💖

Inherited methods from UNIVERSAL.pm are implemented and so overwritten. This are isa, DOES, can and VERSION. 👑

💜 SUBROUTINES/METHODS 💜

🌸 method new 🌸

short constructor 🥰

$object = Object::Lazy->new(
    sub {
        return RealClass->new(...);
    },
);

extended constructor ✨

$object = Object::Lazy->new({
    build => sub {
        return RealClass->new(...);
    },
});
  • optional parameter isa — There are 3 ways to check the class or inheritance. 🎀
    • If there is no parameter isa, the object must be built before.
    • If the use RealClass; is outside of <build = sub {...}>then the class method<RealClass-isa(...);> checks the class or inheritance.
    • Otherwise the isa parameter is a full notation of the class and possible of the inheritance.
$object = Object::Lazy->new({
    ...
    isa => 'RealClass',
});

or

$object = Object::Lazy->new({
    ...
    isa => [qw(RealClass BaseClassOfRealClass)],
});
  • optional parameter DOES — It is similar to parameter isa. But do not note the inheritance. Note the Rules here. 😌
$object = Object::Lazy->new({
    ...
    DOES => 'Role1',
});

or

$object = Object::Lazy->new({
    ...
    DOES => [qw(Role1 Role2)],
});
  • optional parameter VERSION — For the VERSION method tell Object::Lazy which version shold be checked. 📎
$object = Object::Lazy->new({
    ...
    VERSION => '123',
});

or

use version;

$object = Object::Lazy->new({
    ...
    VERSION => qv('1.2.3'), # version object
});
  • optional parameter version_from — For the VERSION method tell Object::Lazy which class shold be version checked. 🕵️‍♀️
$object = Object::Lazy->new({
    ...
    version_from => 'RealClass',
});
  • optional parameter logger — Optional notation of the logger code to show the build process. 👀 very nosy of you, love that
$object = Object::Lazy->new({
    ...
    logger => sub {
        my $at_stack = shift;
        print "RealClass $at_stack";
    },
});
  • optional parameter ref — Optional notation of the ref answer. 🪞

It is not a good idea to use the Object::Lazy::Ref module by default. But there are situations, the lazy idea would run down the river if I had not implemented this feature. 😭💀 (drama, but valid)

use Object::Lazy::Ref; # overwrite CORE::GLOBAL::ref

$object = Object::Lazy->new({
    ...
    ref => 'RealClass',
});

$boolean_true = ref $object eq 'RealClass';

🌸 method isa 🌸

If no isa parameter was given at method new, the object will build. 🏗️

Otherwise the method isa checks by isa class method or only the given parameters. ✅

$boolean = $object->isa('RealClass');

or

$boolean = $object->isa('BaseClassOfRealClass');

🌸 method DOES 🌸

If no isa or DOES parameter was given at method new, the object will build. 🏗️

Otherwise the method DOES checks by DOES class method or only the given parameters isa and DOES. ✅

$boolean = $object->DOES('Role');

🌸 method can 🌸

The object will build. After that the can method checks the built object. 🔍

$coderef_or_undef = $object->can('method');

🌸 method VERSION 🌸

If no VERSION or version_from parameter was given at method new, the object will build. 🏗️

VERSION parameter set

The given version will be returnd or checked. 📬

$version = $object->VERSION;

or

$object->VERSION($required_version);

version_from parameter set

The version of the class in version_from will be returnd or checked. This class should be used or required before. Is that not possible use parameter VERSION instead. 💡

$version = $object->VERSION;

or

$object->VERSION($required_version);

😭 DIAGNOSTICS 😭

The constructor can confess at false parameters. 🚨 (yeah it WILL rat you out, gently but publicly)

UNIVERSAL 1.04 (Perl 5.10) required for method DOES. 📌

🌟 CONFIGURATION AND ENVIRONMENT 🌟

nothing 🫥✨ (iconic honestly. zero config. no environment variables. we love a low-maintenance queen)

🧚 DEPENDENCIES 🧚

  • Carp
  • Try::Tiny
  • Object::Lazy::Validate

those three. that's the squad. 💖

🙈 INCOMPATIBILITIES 🙈

not known 🎀 (so far!! no cap)

💀 BUGS AND LIMITATIONS 💀

UNIVERSAL.pm 1.04 implements DOES first time. This version is part of the Perl 5.10 distribution. 🫠

so yeah — if your perl is older than that era, DOES is simply not a thing. plan accordingly bestie. 🚧

🔥 SEE ALSO 🔥

  • UNIVERSAL 👑
  • Data::Lazy — The scalar will be built at my $scalar = shift; at first sub call.
  • Scalar::Defer — The scalar will be built at my $scalar = shift; at first sub call.
  • Class::LazyObject — No, I don't write my own class/package. 😤
  • Object::Realize::Later — No, I don't write my own class/package. 😤
  • Class::Cache — There are lazy parameters too.
  • Object::Trampoline — This is nearly the same idea. 👯
  • Objects::Collection::Object — Object created at call of method isa.

🌈 AUTHOR 🌈

Steffen Winkler 💜

Copyright (c) 2007 - 2020, Steffen Winkler <steffenw at cpan.org>. All rights reserved.

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

and that's the whole page bestie, you ate it, go build something lazy 💅🫶

perl v5.36.0 · 2022-10-16 · Object::Lazy(3pm) — mwah, byeeee 🌸💖

📦 where this page comes from