Re: Map iteration and modification

[DrPi <314@drpi.fr>]

Le 29/12/2023 à 04:08, Randy Brukardt a écrit :
> "DrPi" <314@drpi.fr> wrote in message
> news:umjuvc$9sp$2@rasp.pasdenom.info...
>> Le 28/12/2023 à 14:53, DrPi a écrit :
>>> Iterate the Map and temporarily store the key nodes to be deleted then
>>> delete the nodes from the key list ?
>>
>> Not clear. Rephrasing it.
>> Using 2 steps by iterating the Map and temporarily store the keys of nodes
>> to be deleted then delete the Map nodes using the key list ?
> 
> If the keys are messy to save (as say with type String), it might be easier
> to save the cursor(s) of the nodes to delete. You would probably want to use
> a cursor iterator (that is, "in") to get the cursors. Code would be
> something like (declarations of the Map and List not shown, nor is the
> function Need_to_Delete which is obviously application specific, Save_List
> is a list of cursors for My_Map, everything else is standard, not checked
> for syntax errors):
> 
>      Save_List.Empty; -- Clear list of saved cursors.
>      -- Find the nodes of My_Map that we don't need.
>      for C in My_Map.Iterate loop
>         if Need_to_Delete (My_Map.Element(C)) then
>              Save_List.Append (C);
>         -- else no need to do anything.
>        end if;
>     end loop;
>     -- Delete the cursors of the nodes we don't want anymore.
>     for C of Save_List loop
>         My_Map.Delete(C);
>     end loop;
> 
> 
That's what I did but I saved the keys (String) instead of the cursors. 
Does it make a difference ? Performance maybe ?

Nicolas
> 
>                      Randy.
> 
>