Re: Data Structures & storage allocated

[Tim McCarthy <twmac@xxxxxxxxxxxxxx>]

When RPG performs an input operation the data from the record is contained
in a buffer area unique for each file defined to the program (basically a
stream of data). Next it performs a series of moves and converts which move
substringed portions of this buffer into storage areas for each field used
within the program (input). RPG creates storage for each input field used
in your program though this is not necessarily contiguous space. When you
declare a data structure you explicitely define storage. RPG moves data
from the buffer to this storage area; it does not have any pointers to the
input buffer. Your data structure subfields are thus offsets from the
storage defined by the DS.

At 11:05 AM 7/8/98 -0400, you wrote:
>Hello all,
>I have a general question about how data structures work when they map
>field names from externally described files:
>Let's say I have this: (in RPG IV)
>D  PAYDTE      
>D        PAYYR               2    0
>D        PAYMT               2    0
>D        PAYDY               2    0
>PAYYR, PAYMT and PAYDY are defined in PAYMASTR, an externally described
>file in this program.  The 1st rec is read from PAYMASTR,  and
>PAYYR = 98, PAYMT = 06, PAYDY = 22.  When storage is allocated for PAYDTE 
>and its subfields, does the PAYYR field defined in the data structure
>actually contain
>98, or does it have the address of the location of PAYYR within the input
>buffer?
>TIA!
>Dave
>+---
>| This is the Midrange System Mailing List!
>| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
>| To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
>| To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
>| Questions should be directed to the list owner/operator: david@midrange.com
>+---
>

+---
| This is the Midrange System Mailing List!
| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
| To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
| To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---