Re: SETLL *START and %EQUAL

[VERNON HAMBERG Owner <vhamberg@xxxxxxxxxxxxxxx>]

Hi Peter


SETLL does not position on a record - with *START it positions before the first record. I think %found doesn't have a way to know about what in the file in this case. Someone can help out here.


Vern


On Thu, 16 Mar, 2023 at 5:21 PM, Peter Dow <petercdow@xxxxxxxxx> wrote:
 

To: rpg400-l@xxxxxxxxxxxxxxxxxx

Yes, I can see that as an explanation for the observed behavior.

A related issue is SETLL *START and %found.  The manual says

"The resulting indicators reflect the status of the operation. You can 
specify an indicator in positions 71-72 that is set on when the search 
argument is greater than the highest key or relative record number in 
the file. This information can also be obtained from the %FOUND built-in 
function, which returns '0' if no record is found, and '1' if a record 
is found."

So I tried

dcl-s wFound ind;

setll *start MyFile;
wFound = %found(MyFile);

and in debug, wFound = '0', even though there are records in the file.

Again, you could say that %FOUND has no meaning when *START is 
specified. But I'd argue that if records exist in a file, then the 
*STARTing record exists. And *START works for keyed and non-keyed 
(arrival sequence) files.


On 3/16/2023 2:55 PM, Therrien, Paul via RPG400-L wrote:
> I've never used *START.
> But it seems to me the %EQUAL has no meaning when you are not providing key values to the SETLL op code.
>
>
>
> -----Original Message-----
> From: RPG400-L<rpg400-l-bounces@xxxxxxxxxxxxxxxxxx<mailto:rpg400-l-bounces@xxxxxxxxxxxxxxxxxx>>  On Behalf Of Peter Dow
> Sent: Thursday, March 16, 2023 5:20 PM
> To: rpg400-l<rpg400-l@xxxxxxxxxxxxxxxxxx<mailto:rpg400-l@xxxxxxxxxxxxxxxxxx>>
> Subject: SETLL *START and %EQUAL
>
> I have a program that has
>
>    SETLL *START MyFile;
>    IF %EQUAL();
>          READ MyFile;
>    ELSE;
>         do something different;
>    ENDIF;
>
> In debug, I discovered that it does something different. My first thought was that maybe it's because the file is empty, but it wasn't.
>
> After reading the manual, the closest thing I can see to saying why %EQUAL was *OFF was this:
>
> "You can specify an indicator in positions 75-76 that is set on when a record is present whose key or relative record number is equal to the search argument. This information can also be obtained from the %EQUAL built-in function, which returns '1' if an exact match is found."
>
> I guess there's an argument to be made that *START is not an exact match with whatever is in the first record, but one could also say that the first record is always a match for the first record.
>
> I also noticed that the manual does not say what the effect of () around the search argument is.  My assumption there is that the () define a list of values that are converted to match the related key fields, but the manual does not say that.
>
> Where is this stuff actually stated?
>
> --
> *Peter Dow* /
> Dow Software Services, Inc.
> 909 793-9050
> petercdow@xxxxxxxxx<mailto:petercdow@xxxxxxxxx>
> pdow@xxxxxxxxxxxxxx<mailto:pdow@xxxxxxxxxxxxxx>
>
> /
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