Re: access assignation. Aliasing problems?

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Javi <fjvera@gmail.com> writes:

> Hi again, I have some problem between access assignations. "List" has
> in its definition a private access to ListNode (First, Last). Why
> can't I do the assignation: L.List := L.Last ? it does produce an
> "accessibilty error check". If both values are null, I can not either
> do the assignation.
>
> -----------
> ...
>    procedure putItem (L : in out List; It : in ItemList) is
>    begin
>       if L.Last = null then
>          L.Last := new ListNode'(Item => It, next => null);
>          print(L.Last.Item); --DBG this prints OK, the Item was
> properly assigned
>          L.First := L.Last; -- this fails, L.First and L.Last are both
> the same type access ListNode
> ...
> ----------
>
>
> I'm very sorry because of bothering you with this simple questions,
> thanks again.

No need to apologize -- your question is a reasonable one.  But you're
more likely to get an answer if you post a complete compilable example,
and explain in detail what "this fails" means.

- Bob