programming_elixer6-chop.exs

defmodule Chop do
  def guess(actual, low..high) do
    n = div(low + high, 2)
    IO.puts "Is it #{n}?"
    _next_guess(actual, low..high, n)
  end

  defp _next_guess(actual, _.._, actual) do
    actual
  end

  defp _next_guess(actual, low.._, n) when n > actual do
    guess(actual, low..n)
  end

  defp _next_guess(actual, _..high, n) when n < actual do
    guess(actual, n..high)
  end
end