Ruby::Enum

Gem Version Build Status Dependency Status Code Climate

Enum-like behavior for Ruby, heavily inspired by this and improved upon another blog post.

Usage

class Colors
  include Ruby::Enum

  define :RED, "red"
  define :GREEN, "green"
end

Referencing

Colors::RED # "red"
Colors::GREEN # "green"
Colors::UNDEFINED # raises Ruby::Enum::Errors::UninitializedConstantError
Colors.keys # [ :RED, :GREEN ]
Colors.values # [ "red", "green" ]
Colors.to_h # { :RED => "red", :GREEN => "green" }

All Enumerable methods are supported.

Iterating

Colors.each do |key, enum|
  # key and enum.key is :RED, :GREEN
  # enum.value is "red", "green"
end

Mapping

Colors.map do |key, enum|
  # key and enum.key is :RED, :GREEN
  # enum.value is "red", "green"
  [enum.value, key]
end

# => [ ['red', :RED], ['green', :GREEN] ]

Reducing

Colors.reduce([]) do |arr, (key, enum)|
  # key and enum.key is :RED, :GREEN
  # enum.value is "red", "green"
  arr << [enum.value, key]
end

# => [ ['red', :RED], ['green', :GREEN] ]

Sorting

Colors.sort_by do |key, enum|
  # key and enum.key is :RED, :GREEN
  # enum.value is "red", "green"
  enum.value
end

# => [ [:GREEN, #<Colors:...>], [:RED, #<Colors:...>] ]

Several hash-like methods are supported.

Retrieving keys and values

Colors.keys
# => [:RED, :GREEN]

Colors.values
# => ["red", "green"]

Mapping keys to values

Colors.key?(:RED)
# => true

Colors.value(:RED)
# => "red"

Colors.key?(:BLUE)
# => false

Colors.value(:BLUE)
# => nil

Mapping values to keys

Colors.value?('green')
# => true

Colors.key('green')
# => :GREEN

Colors.value?('yellow')
# => false

Colors.key('yellow')
# => nil

Contributing

You're encouraged to contribute to this gem. See CONTRIBUTING for details.

Copyright (c) 2013-2015, Daniel Doubrovkine and Contributors.

This project is licensed under the MIT License.