RE: creating a new procedure that callanexistingprocedurewithoneadditional parm

Larry,

My understanding is that there is a difference between

MyProc(parm1:*omit);
MyProc(parm1)


In the first case, the address passed, via the call stack, for the 2 parm is 
*NULL.

In the second case, nothing is passed.  You can't test for it except by check 
%parms to see how many parms were passed.

In other words, in the first case %parms = 2.  In the second case %parms = 1.

When a parameter is declared with *OMIT and *NOPASS, you always have to check 
both cases.

if %parm <=2;    //check for nopass
  if %addr(myParm2) <> *NULL;  //check for *OMIT
    // we have something to work with
  endif;
endif;

//this doesn't work as it depends on some prior call having left zeros in the 
call stack
if %addr(myParm2) <> *NULL;
  // we don't really know what we have
endif;



Here's a good reference:
http://www.itjungle.com/fhg/fhg010505-story02.html


HTH,

Charles Wilt
--
iSeries Systems Administrator / Developer
Mitsubishi Electric Automotive America
ph: 513-573-4343
fax: 513-398-1121
 

> -----Original Message-----
> From: rpg400-l-bounces@xxxxxxxxxxxx
> [mailto:rpg400-l-bounces@xxxxxxxxxxxx]On Behalf Of Larry Ducie
> Sent: Tuesday, July 26, 2005 4:15 PM
> To: rpg400-l@xxxxxxxxxxxx
> Subject: RE: creating a new procedure that
> callanexistingprocedurewithoneadditional parm
> 
> 
> Hi Charles,
>  
> <snip>
> I think it depends on what happens to be in memory at a 
> particular location.
> </snip>
>  
> My understanding is that passing *OMIT into the procedure in 
> place of an
> omittable parm would set the address to null. If it didn't 
> then *OMIT is a
> waste of time.
>  
> For example, if you could omit ONLY the fourth of seven parms 
> you've got no
> way of checking if it's passed without checking it's address 
> - referencing
> the variable directly will cause an exception if it actually 
> was omitted.
>  
> Cheers
>  
> Larry Ducie  
> -- 
> This is the RPG programming on the AS400 / iSeries (RPG400-L) 
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