charcount.rb

class Bag < Hash
  
  def add(obj)
    increment_count(obj)
  end
  
  def increment_count(obj)
    self[obj] = (cnt = self[obj]).nil? ? 1 : cnt + 1
  end
  
  def total
    self.values.inject {|tot, cnt| tot + cnt}
  end
  
  def to_s
    puts "Sum = #{total}"
    keys.sort.each {|key| puts "#{key} = #{self[key]}"}
  end
end

require 'tempfile'
def create_data_file(data)
  file = Tempfile.new('challenge')
  data.each {|d| file.write(d + "\n")}
  file.close
  file
end

# bag of characters
file_of_chars = create_data_file(%w[5 a n 7 4 n 6 1 0 y w a])
bag = Bag.new
file_of_chars.open.each {|line| bag.add(line.rstrip)}
bag.to_s
  # Sum = 12
  # 0 = 1
  # 1 = 1
  # 4 = 1
  # 5 = 1
  # 6 = 1
  # 7 = 1
  # a = 2
  # n = 2
  # w = 1
  # y = 1


# bag of words
file_of_words = create_data_file(%w[Going on vacation yippe on vacation on Sunday])
bag = Bag.new
file_of_words.open.each {|line| bag.add(line.rstrip)}
bag.to_s
  # Sum = 8
  # Going = 1
  # Sunday = 1
  # on = 3
  # vacation = 2
  # yippe = 1