benchmark.rb

require 'benchmark'
iterations = 100_000

Benchmark.bmbm(20) do |bm|
  bm.report('Regexp New') do
    iterations.times do
      'menu'[Regexp.new("^\\b#{Regexp.union(['menu'])}\\b")]
    end
  end

  bm.report('Written Regexp') do
    iterations.times do
      'menu'[/menu/i]
    end
  end

end