Re: Pop function

[Adam Beneschan <adam@irvine.com>]

On Dec 14, 4:29 pm, Martin Dowie <mar...@re.mo.ve.thedowies.com>
wrote:
> "Rego, P." <pvr...@gmail.com> wrote:
> > Hello,
>
> > Given a list type
> >    type T_List is
> >       record
> >          Next : access T_List;
> >          Item : Integer;
> >       end record;
> >    T_List_Ptr is access T_List;
>
> > Is it right to implement a pop function like the following? (Free is an
> > Unchecked_Deallocation)
> >    function Pop (Sender : access T_List) return Integer is
> >       Current_Sender_Ptr : T_List_Ptr := T_List_Ptr (Sender);
> >       Current_Item : constant T_List := Sender.Item;
> >    begin
> >       if Sender /= null then
> >          if Sender.Next /= null then
> >             Current_Sender_Ptr := T_List_Ptr (Current_Sender_Ptr.Next);
> >          end if;
> >             Free (Current_Sender_Ptr);
> >          return Current_Item;
> >       else
> >          return 0;
> >       end if;
> >    end Pop;
>
> > I mean, if I set Current_Sender_Ptr := T_List_Ptr
> > (Current_Sender_Ptr.Next), it's equivalent to Sender := Sender.Next?
> > (which I could not do directly due to in this case it would not be
> > allowed an anonymous reference, right?)
>
> If Sender is null, your in trouble before you get to "begin".

First it's "here" instead of "hear", now it's "your" instead of
"you're"..........

:)
                      -- Adam