one liner for http://blog.mccartie.com/2013/08/19/word-count-exercise.html

gistfile1.rb

class Phrase
  def initialize(words)
    @words = words
  end
  
  def word_count
    @words.downcase.scan(/\w+/).inject(Hash.new(0)) { |list,word| list.merge!({ word => list[word]+1 }) }
  end
end