RE: CHAIN Versus SETLL and READ When Data Needed -- RPG400-L

There was a lot of 'bad mouthing' of iter, leave, etc. yesterday.  How
would you get out of a DOW 0=0 without using them? 

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of rob@xxxxxxxxx
Sent: Thursday, March 01, 2007 8:44 AM
To: RPG programming on the AS400 / iSeries
Subject: Re: CHAIN Versus SETLL and READ When Data Needed

Interesting.  Haven't used procedure pointers.  So, do you think your
coworkers would find the use of procedure pointers clearer than the use
of ITER or LEAVE?

Rob Berendt
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Dept 01.073
PO Box 2000
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6928N 400E
Kendallville, IN 46755
http://www.dekko.com

"Chris Pando" <chris@xxxxxxxxx> 
Sent by: rpg400-l-bounces@xxxxxxxxxxxx
02/28/2007 05:04 PM
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Re: CHAIN Versus SETLL and READ When Data Needed

On 2/28/07, rob@xxxxxxxxx <rob@xxxxxxxxx> wrote:

Yes, actually, it is too much to expect.  I tried to follow that rule

but

it got too ugly with nested if's and stuff to put logic around each

part

to see if it's time to exit
Dou KissOff;
 if this;
   //
 else;
   //
 EndIf;
 If not KissOff;
   if ...;
     //
   EndIf;
 EndIf;
 If not KissOff;
   If ...;
     //
   EndIf;
 EndIf;
 If not KissOff;
   If ...;
     //
   EndIf;
 EndIf;
EndDo;


I have to deal with similar circustances all the time - as an example, I

have
a program with ten (10) consecutive procedures to execute. If any of
them
fail, I want to stop processing.

I create an array (@procProxy@) containing pointers to the procedures,
each of which returns KissOff.

I then create a proxy procedure (procProxy) based upon the procedure 
pointer
procProxy@.

Then my code looks like this:

$I = 0;
DoU ( KissOff Or $I = %Elem(@procProxy@) );
  $I = $I + 1;
  procProxy@ = @procProxy@($I));
  KissOff = procProxy();
EndDo;


The Do loop has a true invariant, and GOTOs aren't necessary.


Chris "IMHFO" Pando
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chris@xxxxxxxxx           | Every normal man must be tempted at
www.pando.org             | imes to spit on his hands, hoist
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