Ruby::Enum
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 and License
Copyright (c) 2013-2015, Daniel Doubrovkine and Contributors.
This project is licensed under the MIT License.
Related Projects
- typesafe_enum: Typesafe enums, inspired by Java.
- renum: A readable, but terse enum.