RE: Quieter Monitors

I was expecting you to suggest a procedure to hide the IFs, but I was
surprised you took it with humor =)

As much as I like Monitor, I agree, the current implementation consumes
too much resources passing around messages. It would have been nice to
have an operation extender to make the message logging optional.

Fortunately, the choice is more about style than anything. For example,
I had to change my former code:

Monitor;
C00FEM = %Char(%Date(E01FIN: *Iso): *Usa0);
On-Error;
C00FEM = *All'0';
EndMon;

To this:

Test(ED) *Iso E01FIN;
If Not %Error();
C00FEM = %Char(%Date(E01FIN: *Iso): *Usa0);
Else;
C00FEM = *All'0';
EndIf;


Not a big deal after all. And don't worry, the zeroed dates are
expected.

--
Saludos
Antonio Salazar

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Rory Hewitt
Sent: Tuesday, February 23, 2010 12:19 PM
To: RPG programming on the IBM i / System i
Subject: Re: Quieter Monitors

Antonio,

Quick answer: Make UngodlyComplexExpression a procedure with a *PSSR
which
returns a blank. Easy! <grin>

Look, I'm not saying that MONITOR is bad, just that it's (very) often
badly
used. For rarely occurring errors, it's a good idea. For common errors,
it's a bad idea, because of the performance hit which happens when an
error
occurs. If the fields in UngodlyComplexExpression frequently include
invalid
values, then advance error checking should be used.

You can't be absolutely sure of anything, but with MONITOR, you get a
blank
part number. With error chekcing which doesn't catch every possible
situation, your program crashes. It's really up to you to say which is a
'better' situation - in many cases, I'd rather have a program crash than
print out 1000 invoices with blank part numbers...

Rory

On Tue, Feb 23, 2010 at 9:50 AM, Jose Antonio Salazar Montenegro <
0jsalazarm@xxxxxxxxxxxxx> wrote:

How about this:

Imagine you have an ungodly complex expression to form a part number

out

of several fields:

// With Monitor
Monitor;
PartNo = UngodlyComplexExpression;
On-Error;
PartNo = '';
EndMon;

// Without Monitor
If Ungodly = www And
(Complex >= yyy And Complex <= zzz) And
...
//Etc.
PartNo = UngodlyComplexExpression;
Else;
PartNo = '';
EndIf;

You can't be absolutely sure that the second example won't throw an
escape message if the source fields (or its constraints) change in the
future.

--
Saludos
Antonio Salazar