Re: How to properly use %EOF() bif?

[Peter.Colpaert@xxxxxxxxxx]

Igor,

I never use %eof after a Chain.

More specifically, I never use Chain to start a loop, always setll + 
read/reade.

Just my opinion of course, others may contradict me.  But I've never 
encountered problems like the one you describe, so I guess my way of 
coding seems to work.

HTH,

Peter Colpaert
Application Developer
Massive - Kontich, Belgium
-----
Yoda of Borg are we.  Futile is resistance, assimilated will you be.
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Igor.Beslic@xxxxxxxxxxxx
Sent by: rpg400-l-bounces@xxxxxxxxxxxx
18/08/2005 16:17
Please respond to RPG programming on the AS400 / iSeries

 
        To:     rpg400-l@xxxxxxxxxxxx
        cc: 
        Subject:        How to properly use %EOF() bif?


Hello!

Recently I've stucked with problem i resolved but still I'm asking for 
explanation. HOW %EOF() bif works? I read that resulting inds are set off 
before performing operations which affect them so I believed that file 
status BIFs (%FOUND, %EOF, %EQUAL..) work similary.


I had program that read keys from array and for every key chained to file 
and read all records with current key. LOOP A describes simplified 
process. 

LOOP A

01 FOR COUNT=1 TO %Elem(keyARRAY);
02 key4file=keyARRAY(COUNT);
03 chain key4file KEYEDFILE;
04 if %Found();
05   dow NOT %Eof();
06      register();
07      reade key4file KEYEDFILE;
08   ENDDO; 
09  endIf;
10 endFor;

The problem is that loop was good just for the first iteration. On second 
iteration, when program successfuly chained to new record with new key, 
%EOF() bif in line 05 returned result that refered to last READE operation 

but not CHAIN. I used this approach because I thought that CHAIN is some 
combination of SETLL+READ but obviosly I was wrong.

I altered LOOP with SETLL and READ operations as in LOOP B example and now 

program process all records with keys in keyARRAY:
LOOP B

01 FOR COUNT=1 TO %Elem(keyARRAY);
02  key4file=keyARRAY(COUNT);
03  setll key4file KEYEDFILE;
04  if %Equal();
05    read KEYEDFILE;
06    dow NOT %Eof();
07         register();
08         reade key4file KEYEDFILE;
09    ENDDO;
10  endif;
11 endFor;

Now I'm asking is it restricted to perform only read{E,P} operations 
before using %EOF or %BOF built in functions??

Best regards,
Igor Bešlić, dipl. ing. rač. 
VOLKSBANK d.d.
OJ Informatika
Zelinska 2, 10000 Zagreb
tel: +385 1 6326422