RE: What's the difference?

["Bob Cozzi" <cozzi@xxxxxxxxx>]

You are wrong.
Procedures need to have the *NOPASS specified otherwise the compiler
will not let you call them with missing parameters. Which you obviously
already know.
Programs, on the other hand, work a little differently. When a program
calls another program and passes parameters, the parameters are not
checked to see if they match what is required by the called program.
As the called program runs, if it "touches" any of the parameters then
the check is performed. Now "touching" a parameter can take on many
forms. But if you use a simply *ENTRY/PLIST without mapping the parms
into a data structure, then you can also use %PARMS to check for
un-specified parameters and simply avoid touching them. This allows you
to call a program with 10 parameters defined and only pass 3.  Just
don't touch parms 4 through 10 and you can get away with anything.
Bob Cozzi

-----Original Message-----
From: rpg400-l-admin@midrange.com [mailto:rpg400-l-admin@midrange.com]
On Behalf Of Bartell, Aaron L. (TC)
Sent: Monday, November 18, 2002 10:08 AM
To: 'rpg400-l@midrange.com'
Subject: RE: What's the difference?

I should have given an example.  Below I have an example of a
sub-procedure
doing a chain to a file (DB separation concept).  If I want to lock the
file
I pass the last parameter.  If I don't want it locked I don't even have
to
know that there is a last parameter.  If I tried to do this from one
program
to another vs from a program to sub-procedure I would get a "pointer not
set. . ." type message.  Correct me if I am wrong.

     P chainFile01     B                   export
     D chainFile01     pi             1
     D  pKey1                         3  0 value
     D  pKey2                         3  0 value
     D  pKey3                        20    value
     D  pLock                         1    value options(*nopass)
      *------------------
     C     kFile01       klist
     C                   kfld                    pKey1
     C                   kfld                    pKey2
     C                   kfld                    pKey3

     C                   if        %parms = 3 or pLock = *off
     C     kFile01       chain(n)  File01
     C                   else
     C     kFile01       chain     File01
     C                   endif

     C                   return    %found(File01)
      *-------------------------------
     P chainFile01     E

Program that uses above sub-procedure:
 * lock the file
C          callp      chainFile01(Key1:Key2:Key3:*on)
 * dont lock the file
C          callp      chainFile01(Key1:Key2:Key3)


Aaron Bartell

-----Original Message-----
From: Buck Calabro [mailto:Buck.Calabro@commsoft.net]
Sent: Monday, November 18, 2002 9:56 AM
To: rpg400-l@midrange.com
Subject: RE: What's the difference?


>To add to Buck's list I also like the ability
>to NOT pass a parameter if it is not needed
>-- options(*nopass).

The called program can test %parms just like a subprocedure can, so I
think
this works for procs and progs.

c     *entry        plist
c                   parm                    inCount

c                   if        %parms < 1
c                   eval      loopLimit = 1000
c                   else
c                   eval      loopLimit = inCount
c                   endif

  --buck
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