     case string do
       <<prefix::size(prefix_size)-binary, suffix::binary>> when prefix == match ->
         prepend_unless_empty(replacement, suffix)
+
       _ ->
         string
     end

      123

  """
  @spec to_integer(String.t) :: integer
  def to_integer(string) do
    :erlang.binary_to_integer(string)
  end

      printable?(rest, decrement(counter))
    end
  end

  for char <- '\n\r\t\v\b\f\e\d\a' do
    def printable?(<<unquote(char), rest::binary>>, counter) do
      printable?(rest, decrement(counter))
    end
  end

  def printable?(<<char::utf8, rest::binary>>, counter)
      when char in 0xA0..0xD7FF
      when char in 0xE000..0xFFFD
