kindergarten_garden.rb

class Garden
  
  attr_accessor :first_row, :second_row
  attr_reader :names
  
  CHARS_TO_PLANTS = {
    "G" => :grass,
    "C" => :clover,
    "R" => :radishes,
    "V" => :violets
  }
  DEFAULT_STUDENTS = [:alice, :bob, :charlie, :david, :eve, :fred, :ginny, :harriet, :ileana, :joseph, :kincaid, :larry]
  
  def initialize(garden, students = DEFAULT_STUDENTS) 
    rows = garden.split("\n")
    @first_row = rows[0]
    @second_row = rows[1]
    @names = Garden::StudentFormatter.new(students).format
  end
  
  def get_plants(name)
    plants_for(name).collect do |letter|
      CHARS_TO_PLANTS[letter]
    end
  end
  
  def plants_for(name)
    index = @names.find_index(name)
    [@first_row[index * 2], @first_row[index * 2 + 1]].concat([@second_row[index * 2], @second_row[index * 2 + 1]])
  end
  
  def method_missing(name, *args, &block)
    super unless @names.include?(name)
    get_plants(name)
  end
end

class Garden::StudentFormatter
  
  attr_accessor :data
  
  def initialize(data)
    data_classes = data.collect { |student| student.class }
    @data = Hash[data.zip(data_classes)]
  end
  
  def format
    @data.collect { |name, klass| klass.format_student(name) }.sort
  end
end

class String
  def self.format_student(student)
    student.downcase.to_sym
  end
end

class Symbol
  def self.format_student(student)
    student
  end
end