Enum

This is a very basic implementation of enums in Ruby. The cornerstone of the library is safety.

Installation

Add this line to your application's Gemfile:

gem 'enum', require: 'enum'

And then execute:

$ bundle

Or install it yourself as:

$ gem install enum

Usage

Define set of enums with code like this:

class Side < Enum::Base
  values :left, :right
end

Now take safely defined values by argument with its Symbol or String type. If there is no defined such value Enum::TokenNotFoundError exception will be raised. And this is the safety - you will be noticed about the problem and fix it by introducing a new value or fixing a source of the invalid value. While others implementations of enums in Ruby (that I know) just silently ignore invalid values returing nil this one will raise the exception always. Example of usage:

Side.take(:left) # => "left"
Side.take('left') # => "left"
Side.take(:invalid) # => Enum::TokenNotFoundError: token 'invalid'' not found in the enum Side
Side.take('invalid') # => Enum::TokenNotFoundError: token 'invalid'' not found in the enum Side

If you have installed I18n in your application feel free to use name method to retreive the values' translations. For the given example the possible translation structure in yml format is the following:

en:
  enum:
    Side:
      left: 'Left'
      right: 'Right'

The name method usage example:

Side.name(:left) # => "Left"
Side.name('left') # => "Left"
Side.name(:right) # => "Right"
Side.name('right') # => "Right"
Side.name(:invalid) # => Enum::TokenNotFoundError: token 'invalid'' not found in the enum Side

If you don't have installed I18n in your project NameError exception will be raised on the name method call.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/mezuka/enum. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.