Re: Multi-field dynamic array

Well, with this size array, you can only fit just over 1000 elements into
the DS (64k max), so if this will always be a suitable amount, just
DIM(1170), and keep track of the number of elements, to speed up %Lookup
slightly.

If you need more elements than 1,170, it gets a bit trickier.  You have to
create a user space, allocate a pointer to it, and create a single BASED DS
that is based on the pointer, and 'walk' the pointer through the user space,
incrementing it by the size of the DS (56 bytes).  Instead of %lookup, you
would use the qsort() and bsearch() API.

I have only done this once, and it didn't make it to production, so the best
place for this example would be the Redbook, "Who knew you could do that
with RPGIV?  A Sorcerer's Guide to System Access and More".

There is also a way to directly allocate memory, and use that instead of a
user space, but I have never done this myself.

On 1/11/06, Grizzly M <grizzlym@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> I'm sure this has been asked before but I can't seem to find what I'm
> looking for in the archives
>
> I'll post the code that I have to help paint the picture
> D AddItmIdx       S              5S 0 Inz(0)
> D BuyItmIdx       S              5S 0 Inz(0)
> D                 DS
> D BuyerInfo                     56A   DIM(1)
> D   Buyer                        3A   Overlay(BuyerInfo:1)
> D   Item                        27A   Overlay(BuyerInfo:4)
> D   Quantity                    11S 2 Overlay(BuyerInfo:31)
> D   LastPurch                    8S 0 Overlay(BuyerInfo:43)
> D   Vendor                       6A   Overlay(BuyerInfo:51)
>
> /Free
>
> BuyItmIdx = %LookUp(PBITNO:Item);
> IF BuyItmIdx > 0;
>     Quantity(BuyItmIdx) = PBORQT;
>
>     If WrkDate > LastPurch(BuyItmIdx);
>        LastPurch(BuyItmIdx) = WrkDate;
>     EndIF;
>
> Else;
>     AddItmIdx += 1;
>     Buyer(AdditmIdx) = PBVNNO;
>     Item(additmidx) = PBITNO;
>     Quantity(Additmidx) = PBORQT;
>     LastPurch(AddItmIdx) = WrkDate;
>     Vendor(AddItmIdx) = PBVNNO;
> EndIF;
>
> /Free
> I want to be able to increase the size of the array on an as needed
> basis. I'm pretty sure this can be done with pointers, but I can't
> figure out how. Can anyone offer some suggestions?
>
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