Given a function generate_numbers which generates a large amount of numbers.

def generate_numbers() do
    n = 20000000 # a very large number
    for l <- 1..n,
        d <- 1..n,
        h <- 1..n,
        w <- 1..n do
      [ l,  d,  h,  w ]
    end
end

and also an imaginary function to consume the list

def consumer() do
  Stream.each(generate_numbers, fn e ->
     do_something(e)
  end)
  |> Stream.run()
end

The for loop is accumulating all [ l, d, h, w ] which is a big list and consumer has to wait for the whole list to be passed.

How can I make generate_numbers to return/yield each generated [ l, d, h, w ] efficiently and pass it one by one to a caller?

I was thinking I can use into: IO.stream(:stdio, :line) to turn the result into a “stream-able” manner but apparently it only stream the result into standard IO.