Advent of code day 1 solution in Elixir

advent1.exs

defmodule Advent1 do
  def part1("(" <> rest, count) do
    part1(rest, count + 1)
  end

  def part1(")"<> rest, count) do
    part1(rest, count - 1)
  end

  def part1("", count), do: count

  def part2(_, -1, pos), do: pos - 1

  def part2("(" <> rest, count, pos) do
    part2(rest, count + 1, pos + 1)
  end

  def part2(")" <> rest, count, pos) do
    part2(rest, count - 1, pos + 1)
  end
end