unionvalue
Allows easy creation of immutable union values, a.k.a. sum-types.
You can think of them as enums (enumerated types) that can also contain other data.
Example:
APICallResult = UnionValue.new(:success, :failure, :timeout)
APICallResult.failure.is_failure? #=> true
APICallResult.timeout.is_success? #=> false
APICallResult.success(12345).data #=> 12345
Normal classes with attributes act as 'product' types. In other words, their number of possible values are the product of the number of possible values of all their attributes. Sum-types are instead just the sum of their attributes values. In other words, they can have this attributes OR this other attribute, but not both.
Read more about sum-types here: https://en.wikipedia.org/wiki/Sum_type
Copyright
Copyright (c) 2015 Axis Sivitz. See LICENSE.txt for further details.