Hash#p_diff

hash-p_diff.rb

class Hash
  def p_diff(b)
    merged_keys = keys | b.keys
    merged_keys.each do |k|
      case
      when key?(k) && b.key?(k)
        value = self[k]
        if value == b[k]
          puts "a,b: #{k.inspect} => #{value.inspect} == #{b[k].inspect}"
        else
          puts "a,b: #{k.inspect} => #{value.inspect} != #{b[k].inspect}"
        end
      when key?(k)
        puts "a: #{k.inspect} => #{self[k].inspect}"
      when b.key?(k)
        puts "b: #{k.inspect} => #{b[k].inspect}"
      else
        raise
      end
    end
  end
end