Value.WaitFor.pqm

(producer as function, interval as function, optional count as number) as any =>
    let
        list = List.Generate(
            () => {0, null},
            (state) => state{0} <> null and (count = null or state{0} < count),
            (state) =>
                if state{1} <> null then
                    {null, state{1}}
                else
                    {1 + state{0}, Function.InvokeAfter(() => producer(state{0}), interval(state{0}))},
            (state) => state{1}
        )
    in
        List.Last(list)