I think this would mean that the code would look nicer. I may be misunderstanding, but I think the two versions of tail-recursive factorial would look like this:

```haskell
factorial accum n =
    Trampoline <| if n <= 1 then Left accum else Right (() -> factorial (n*accum))

factorial accum n =
    if n <= 1 then Done accom else Continue (() -> factorial (n*accum))
```