Non destructive summation of nodes (Linked List/FIFO Queue)

["Liddle Feesh" <no_see_reply_address@spam.com>]

Hi,

Firstly - thankyou to everyone (Larry Hazel, Gautier, Ed Falis, Michal
Nowak, Machael Bode & others) for your kinds assitance in helping me take my
first steps in the great language of Ada95.

I am a little confused, however - at how to count the number of items in a
linked list, without destroying the items in the process.

Basically, I want to do this:

If queue is empty
        display warning message
Else
        loop while next pointer on node is not null
                    print node's value
        end loop
        print last node's value
end if

*So that I can loop through all the nodes. If this isn't possible, then
another solution could be:*

Declare Count_Of_Elements as Integer
Set Count_Of_Elements = 0
While Not Queue.Head = null
          Increment Count_Of_Elements = Count of Elements + 1 -- (Increment
Count)
End Loop
Print Count_Of_Elements


----
However, writing the above in Ada without destroying the queue is tricky.
Michal suggested:

while not (Queue.Is_Empty_Queue(Queue) ) loop
        Queues.Remove (Element, Queue);
        Put(Element);
        New_Line;
end loop;

------

However, the above basically removes each node whilst 'counting' back the
values stored in each.

And for those that have just joined this conversation, I am trying to create
a display function/procedure that gives me a count of the elements in the
queue.

TIA!

Mike

--
Liddle Feesh
 '  O 0 o <"//><  ' o'^
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