Re: SETLL *START and %EQUAL

[Alan Cassidy <cfuture@xxxxxxxxxxx>]

I would rephrase Jon's explanation this way.

When you use SETLL using the key field values for the file you're 
reading, you get %equal = '1' if it finds a record with keys that match 
those values. If you key field "valules" is *START, you aren't giving 
the statement any arguments to match against the key fields. "Whatever 
you get" is meaningless, because the question becomes, "Equal to what, 
exactly?"

--Alan Cassidy


On 3/16/2023 6:21 PM, Jon Paris wrote:
> I don't think $equal should be set here as it used to indicate that it detected a record in the file with a key equal to that of the value specified. But no valid key was specified!
>
> Remember that SETLL is attempting to position the read cursor _before_ the first record with the desired key. Telling you that it was able to exactly match (i.e. %equal) is basically just a useful courtesy. If you think of it that way the failure to set %equal may make more sense.
>
> As to the second part of your question, I'm not sure where it is documented - but as a general rule parens mean "this key may not be in the exact right format - please deal with it." - so a packed number will be accepted for a zoned key for example.  In the case of *Start they are meaningless.
>
>     
> Jon P.
>
> > On Mar 16, 2023, at 5:19 PM, Peter Dow <petercdow@xxxxxxxxx> wrote:
> >
> > 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
> > pdow@xxxxxxxxxxxxxx
> >
> > /
> > --
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