Elixir dictionary binary search

words.exs

defmodule Words do
  @doc """
  Module for read a list of words from a text file.
  Contains functions for `split`ting the list and `find`ing a word
  """
  def read(filename) do
    filename
    |> File.read!()
    |> String.split()
  end

  def split(list) do
    mid = div(length(list), 2)
    Enum.split(list, mid)
  end

  def find(word, words) do
    {first_half, second_half} = split(words)
    
    guess = (List.last(first_half) || List.first(second_half))
    |> String.downcase

    cond do
      word < guess ->
        IO.puts("Less than: #{guess}")
        find(word, first_half)
      word > guess ->
        IO.puts("Greater than: #{guess}")
        find(word, second_half)
      :else ->
        IO.puts("Found word: #{guess}")
        word
    end
  end
end

defmodule Random do
  @doc """
  Module for choosing a psudo-random element from a list
  """
  def init do
    :random.seed(:os.timestamp)
  end 
  def random_element(list) do
    Enum.at(list, :random.uniform(length(list)) - 1)
  end
end

# Entry point

# Set the random seed
Random.init
# Choose a random word
word = Random.random_element(words)
# Read the UNIX words dictionary
words = Words.read("/usr/share/dict/words")
IO.puts("Word is: #{word}")
# Perform the binary search to "guess" the word
Words.find(word, words)