/ 
Class-Enumeration-v1.0.0
/ Class::Enumeration::Builder

NAME

Class::Enumeration::Builder - Builder module for enum classes

SYNOPSIS

# Setup enum class in a separate module and build it at compile time
use strict;
use warnings;

package TrafficLight;

# Pre-declare the to_string() method to prepare overriding stringification
use subs 'to_string';

# 'action' is a custom attribute
use Class::Enumeration::Builder (
  GREEN  => { action => 'go' },
  ORANGE => { action => 'slow down' },
  RED    => { action => 'stop' }
);

sub to_string {
  my ( $self ) = @_;

  $self->action . ' if ' . $self->name
}

1

# Build enum class at compile time and export enum constants
use strict;
use warnings;

package ToastStatus;

# Choose an exporter module and set the 'export' option to true
use Exporter qw( import );
use Class::Enumeration::Builder { export => 1 }, qw( bread toasting toast burnt );

1

# Build enum class at runtime
my $class = Class::Enumeration::Builder->import(
  { class => 'CoffeeSize' },
  BIG          => { ounces => 8 },
  HUGE         => { ounces => 10 },
  OVERWHELMING => { ounces => 16 }
);

DESCRIPTION

Class::Enumration::Builder builds enum classes. Each such class will be a child class of the abstract parent class Class::Enumeration. The builder creates getters for custom attributes and as a final mandatory step prepares a list of enum objects.

The import() class method implements the build process. Its first argument is an optional HASH reference. The allowed options are class (a non-empty string) and export (a boolean value). The import() method returns the name of the enum class.

If the export option is set to true, the builder will prepare enum constants that are stored in the variable @EXPORT_OK and it will create an :all that is part of the variable %EXPORT_TAGS. Any exporter module chosen and loaded separately enables the feature to export enum constants.

An enum class build setup can be part of a separate module. In this case the build process happens at compile time. The enum class name equals the package name. If you want to override the default stringification you have to pre-declare the to_string() before loading the builder.

An enum class can be build at runtime too. The class option should be used to set the enum class name.

AUTHOR

Sven Willenbuecher <sven.willenbuecher@gmx.de>

COPYRIGHT AND LICENSE

This software is copyright (c) 2025 by Sven Willenbuecher.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.