Re: Looping through an array with FOR EACH

[Gianluigi <gradobag@xxxxxxxxxxx>]

Il 17/01/26 01:01, Benoît Minisini ha scritto:
> Le 17/01/2026 à 00:00, Brian G a écrit :
> > On 1/16/26 14:15, Jussi Lahtinen wrote:
> > > Long time ago Benoit said about collections: "The hash table elements 
> > > are linked both by hash slot and insertion order. But I don't 
> > > guarantee that this non-official feature won't be removed.".
> > > So, For Each is not guaranteed to iterate the elements in the 
> > > insertion order.
> > >
> > >
> > > Jussi
> > Yes this is very obvious, as it is probably a hash table, or tree
>
> Everything is in the source code. :-)
>
> 'Collection' is a hash table, whose nodes have three links:
>
> - A link to the next element having the same hash, or NULL if it is the 
> last one.
>
> - A link to the element previously inserted or NULL if it is the first.
>
> - A link to the next inserted element, or NULL if it is the last one.
>
> The Collection itself maintain a link to the first inserted element, and 
> slots for the different possible hashing values.
>
> So having elements ordered in a collection requires two pointers (16 
> bytes on 64 bites) for each element.
>
> This might be a problem if you need a collection with millions of 
> elements and don't need to maintain the order of insertion.
>
> But even if I said "order is not guaranted", I don't think this feature 
> will be removed.
>
> And if really an hash table with no order to save memory is required, I 
> will add an "HashTable" class for that, to keep backward-compatibility.
>
> So the "not guaranted" guaranty may become "guaranted" in the future.
>
> Regards,

Hi Benoit,

So collections also guarantee insertion order.
Also because you can only add, right?
Speaking of adding, there was a mistake in the example (Add) that I took 
the liberty of correcting.

Regards
Gianluigi