Re: packed v zoned in compiles

[Scott Klement <klemscot@xxxxxxxxxxxx>]

> RPG program compile listing shows the file with
> some zoned fields like     VNTIME     11      16  0
> but the list of fields at bottom of compile listing have
> VNTIME     P(6.0)

Hmmm... I'm surprised that you haven't run into this before.

Every numeric field defaults to packed unless you explicitly tell it
otherwise.  An easy way to tell it to use the same settings as the file is
to declare an external data structure...

> Why?      same in both V5r1 and V5r2

It's always worked this way... all the way back to RPG III on the S/38.
Every release of RPG III or RPG IV works this way.

As I recall, there were two reasons for this.  The first was that the
machines were optimized for packed decimal back in the S/38 days.  The
second was that you're allowed to have fields be read in from many
different files -- by forcing them all to use the same data type (packed)
they don't conflict.   For example, let's say you store the field "PRICE"
as 9P 2 in your PF.  In your display file you have the same field name
"PRICE", but it has to be zoned (9S 2) because packed is not human
readable and therefore doesn't work well on a display.   Since RPG
converts the fields from both files to packed for you, you can simply READ
the PF, and EXFMT the display.  You don't have to rename the fields to
avoid a data type conflict, and you don't have to explictly move from one
to the other.  RPG makes them all consistent by converting them to packed.

At any rate, none of this is new.  I remember doing this on one of the
first releases of OS/400 -- having to force my RPG III variables to be
zoned with a data structure.   It certainly isn't going to change now, as
that would break compatibility.

Here's a link to a previous discussion about this in the archives. You
might find that discussion enlightening...
http://archive.midrange.com/rpg400-l/200202/threads.html#00103