Using a modified example from {coro}, it is unclear how to access the value of the function. Here we return n after the async function has completed.

async_count_down <- coro::async(function(n) {
  while (n > 0) {
    cat("Down", n, "\n")
    coro::await(coro::async_sleep(1))
    n <- n - 1
  }
  n
})

n <- async_count_down()

Running this results in a promise (expected) however, trying to get the value via n$finally() results in an error.

At present it seems that using async() is intended only for functions with side effects. Is that correct?