Re: Field interpreted differently between physicalandlogical

Rick.Chevalier@xxxxxxxxxxxxxxx wrote:
> <snip>
> If you don't explicitly define the field with a D spec, the compiler will 
> assign a default definition for the field.
> </snip>
> 
> The I spec is created from an externally defined file.  Are you saying I need 
> to go backwards and define the file internally?  That doesn't make any sense.

No, making it program-described wouldn't help.  If you have a zoned
field on a program-described I spec, it would default to being packed in
the program same as an externally-described I spec.

> 
> <snip>
> To get all your input fields to be defined internally the same way they are 
> defined in the file, use an externally-described data structure in your 
> calling program:
>    D               e ds                  extname(ISFQE201:ISFQE2R)
> </snip>
> 
> How does this fit into the program though?  Is it merely to set the field 
> definitions?  The data structure in the copybook is defined as externally 
> described so aren't I already doing that?

Indeed, the external DS is merely to set the field definitions.  The one
in the copybook is setting a different set of fields (DS.X and DS.Y vs X
and Y).

> 
> In reference to Matt's post, is it the QUALIFIED keyword that is causing the 
> problem?  I wanted the DS from the copybook qualified to avoid confusion 
> between actual file fields and DS fields in bound programs that use the 
> copybook for prototypes.
> 

I think that was a good decision.  You are right to use QUALIFIED in the
copy file, because of potential conflict with programs it's copied
into.  If a particular program wants to get explicit definitions for the
unqualified names, it should define its own external ds.

This whole external-format vs internal-format is basic to RPG; it's in
RPG II and RPG III too.  Since an I spec doesn't define the field, you
can have the same field appearing on different I specs with different
numeric types:

IFILE1
I              1    5S 0        FIELD1
IFILE2
I              1    3P 0        FIELD1
IFILE3
I              1    2I 0        FIELD1

If FIELD1 is not defined explicitly, it would be packed(5,0) in the
program.  If it was defined explicitly, any of zoned(5,0), packed(5,0)
or integer(5,0) would be valid.