Ruby result matching.rb

module OperationResult
  def Success(value)
    Results::Success.new(value)
  end

  def Failure(value)
    Results::Failure.new(value)
  end

  module Results
    class Result
      def initialize(value)
        @value = value
      end
    
      def success
      end

      def failure
      end

      def match
        yield self
      end  
    end

    class Success < Result
      def success
        yield @value
      end
    end

    class Failure < Result
      def failure
        yield @value
      end
    end  
  end
end

class Service
  include OperationResult  

  def self.call(a)
    new(a).call
  end 
  
  def initialize(a)
    @a = a
  end 

  def call
    if @a
      Success(@a)
    else
      Failure(:some_error)
    end
  end
end

Service.call(1).match do |result|
  result.success do |value|
    p "success #{value}"
  end

  result.failure do |error|
    p "error #{error}"
  end
end