Re: Simple RPG question (because the docs are worthless)

RPG CAFE on DeveloperWorks can sometimes be really helpful. This is from
Barbara in 2012.
Just search for "Eval M".

The M extender tells the compiler to reduce the chance of overflow for a
sub-expression by maximizing the number of integer places in the compiler
temporaries. So if a temporary value might need to have 75 digits and 20
decimal places (55 integer places), the compiler would make it 63 digits
and 8 decimal places (keeping 55 integer places).

The R extender tells the compiler to reduce the chance of loss of
accuracy for a sub-expression by not letting the number of decimal places
in the compiler temporaries go below the number of decimal places in the
result. So if you have

res = (x / y) * p + (q / r / s)




From: john erps <jacobus.erps@xxxxxxxxx>
To: "RPG programming on the IBM i (AS/400 and iSeries)"
<rpg400-l@xxxxxxxxxxxx>
Date: 02/20/2018 08:10 AM
Subject: Simple RPG question (because the docs are worthless)
Sent by: "RPG400-L" <rpg400-l-bounces@xxxxxxxxxxxx>



Hi,

What does the "operation extender" M means I know R and H, but not M.

I tried to look into the RPG docs, at opcode "eval" which seems to me a
logical place to document this, but no. The extenders are mentioned but i
can't find the doc for M (or R or H). When i click "precision rules" i get
to see doc about "operation extender" R.

Man how bad is the RPG documentation on IBM's site. It's terrible.
How on earth is somebody not already having 20+ years of experience in RPG
ever going to find some info. A simple function like "half adjust" is
buried as some "operation extender" (instead of a normal half-adjust
function or BIF or whatever), and the doc on this "operation extender" H
is
almost impossible to find.

Pff, the only thing worse would be no doc at all. Terrible.


Sorry for the rant...