class RandomWords::Generator

def sentence_length=(length)
  to_set = case length.to_s
           when /^s/
             :short
           when /^m/
             :medium
           when /^l/
             :long
           when /^v/
             :very_long
           else
             raise ArgumentError, "Invalid length: #{length}. Use :short, :medium, :long, or :very_long."
           end
  @sentence_length = to_set
end