class YieldParser

  Result = Struct.new(:number, :label)

  def self.parse(yield_string)

    match = /(\d+(?:\.\d*)?)\s*(\w[\w\s]*)?/.match(yield_string)

    case
      when match.nil?
        nil
      when match[2]
        Result.new(match[1].to_f, match[2].strip.singularize)
      else
        Result.new(match[1].to_f, 'each')
    end
  end

end