Who uses the second meaning? In my experience, "purely functional" always means "you can express pure functions on the type level" (thus guaranteeing that it i

Who uses the second meaning? In my experience, "purely functional" always means "you can express pure functions on the type level" (thus guaranteeing that it is referentially transparent and has no side effects) -- see https://en.wikipedia.org/wiki/Pure_function https://en.wikipedia.org/wiki/Pure_function