gowrizrh

# binary pattern matching, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.

defmodule Main do
  def str_str(haystack, needle) do
    match(haystack, needle, 0)
  end

  def match(<<s, str::binary>>, <<s, needle::binary>>, index) do
    needle_len = needle |> String.length()