Tail call optimization for Ruby

tailcall_optimization.rb

# @see [Rubyの末尾呼び出し最適化を試す - Qiita](https://qiita.com/rsnni/items/8f818f2c2da07896fc7e)
RubyVM::InstructionSequence.compile_option = {
  :tailcall_optimization => true,
  :trace_instruction => false
}

RubyVM::InstructionSequence.new(<<-EOS).eval

def fact(x)
  return 1 if x == 0
  fact(x - 1) * x
end

def fact_tail_call(x, m = 1)
  return m if x == 0
  fact_tail_call(x - 1, x * m)
end

EOS