That quote is hilarious -- Guido von Rossum claims that it's impossible to implement `reduce` in a few lines in a functional language. Just out of curiosity, I checked out the `reduce` implementation in Elixir:

  def reduce(enumerable, fun) do
    result =
      Enumerable.reduce(enumerable, {:cont, :first}, fn
        x, :first -> {:cont, {:acc, x}}
        x, {:acc, acc} -> {:cont, {:acc, fun.(x, acc)}}
      end)
      |> elem(1)

    case result do
      :first -> raise Enum.EmptyError
      {:acc, acc} -> acc
    end
  end

Seems pretty straightforward to me.

https://github.com/elixir-lang/elixir/blob/v1.7.4/lib/elixir...