dog2.rb

require 'benchmark'

class Dog

  def say(*words)
    puts 'Doggie says: ' + words.slice(1, words.length - 1).join(' ')
  end

  def method_missing(method, *args, &block)
    if /^say_\B/ =~ method.to_s
      words = method.to_s.split('_')
      say(*words)
    end
  end
end

Benchmark.bm(7) do |x|
  x.report { (1..100000).each { |x| Dog.new.say_woof! } }
end