scala_option.rb

class Option
end

class None < Option
  def map(&block)
    return None
  end
end

class Some < Option
  def initialize(value)
    @value = value
  end

  def map(&block)
    return Some(block.call(@value))
  end
end

None = None.new

def Some(value)
  Some.new(value)
end


def method(input)
  result = input.map { |v| "#{v} day" }.map { |v| "very #{v}" }
end

method(Some("happy")).map { |r| puts "Our result: #{r.inspect}" }
# Prints: very happy day

method(None).map { |r| puts "Our result: #{r.inspect}" }
# Prints nothing