Problem with array updates

[Martin Wierich]

Hi Pablo,

"Pablo J. Pedemonte" wrote:

> I can't mark the array as unique, for I would force the whole VEBTree type
> to be unique. In this case, I can't use the function createArray (not even an
> array comprehension) to initialize it, for they seem to need a non unique elem
> as parameter (I am right?). I get the following error message:
>
> "createArray ({})" attribute at the indicated position cannot be coerced: ^ VEBTree Int

I think the only way to create an array that contains unique objects is to convert a list
into an array. Therefore use an array comprehension:

::  VEBTree u
    = EmptyVEB u
    | ManyVEB u .{VEBTree u} (VEBTree u)

initialize i u
    = ManyVEB u { EmptyVEB u \\ u <- (repeatn i u)} (EmptyVEB u)

update_destructively (ManyVEB u array subtree)
    = ManyVEB u { array & [0] = EmptyVEB 100 } subtree

Start = (initialize 2 0, update_destructively (initialize 2 0))

greetings
  Martin Wierich