Re: DDS arrays

[dhandy@xxxxxxxxxxx (Douglas Handy)]

Jim,

>I am converting a S/36 flat file to native.  Within this file are an
>"array" of numbers.

(snip)

>I would like to be able to do something in RPGIV similar to this, 

Here is what I do:  create an array based on a pointer, then
initialize the pointer to the address of the first field (which would
also become the first array element).  This makes the array an overlay
of the subfields, and no moves are necessary.

To make this work, the fields need to be in a DS to force them to be
contigous in storage.  If the file is named as an external DS, then
that will work provided the fields are contigous in the definition.
If you don't use an external DS for the file, then code a DS and name
the subfields but *don't* define the type/size.  This makes future
maintenance easier.  Here is an example:

     D                 DS

     D D601

     D D602

     D D603

     D D604

     D D605

     D D606

     D D6Ptr           S               *   Inz(%addr(D601))

     D D6              S                   Dim(6) Based(D6Ptr)
     D                                     Like(Oqa01)

With an external DS and contiguous fields, you only need to add the
based array and initialized pointer definitions.

Doug
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