Re: NEW RPG RFE - %Pos() BIF

[Craig Richards <craig@xxxxxxxxxxxxxxxx>]

I think the comment was more directed at the idea that you need to use a
Datastructure to organise how the fields are stored in memory if you have
any intention of basing other fields over them. You can't just assume they
will be stored in the program in the order they appear in the database file.

Personally, I'm quite happy to have an array based on a Pointer and then
use %Addr() to put the Pointer where I want the array to start.
But I understand that not everyone is comfortable with this technique.

However I wouldn't do that without first using a DS to ensure that the
fields were going to be stored how I expect.
Either a DS I have keyed, with just the fields I want, or using ExtName
based on the file ( assuming the fields are on the file in the correct
sequence ) because It's easier.

I would say the main difference with doing that and the %POS BIF that Jon
is suggesting, is that everything is grouped together in the DS ( The
fields from the file, and the array you have defined over the same storage
) and it is not able to be moved around.
So it's clearer and less prone to scullduggery.

But of course that's just my interpretation :-)
best regards,
Craig



On 15 June 2018 at 15:54, Dan <dan27649@xxxxxxxxx> wrote:

> Jon, forgive my ignorance.  I saw that you warned against using a pointer
> to mark the beginning of an array per Craig's comment in Alan's OP based on
> his experience that he'd seen that an array of fields that appear in
> sequence in the definition may not appear that way in the input buffer, so
> I am unsure why you think that a %POS BIF would fix that.  It just seems to
> me to be an easier way to define what is essentially a pointer.  What am I
> missing?
>
> - Dan
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