Re: Static Variables in a subprocedure

["Chris Pando" <chris@xxxxxxxxx>]

On Feb 7, 2008 4:02 PM, Barbara Morris <bmorris@xxxxxxxxxx> wrote:
> Barbara Morris wrote:

> I forgot to say that using EXTPROC('myproc') will only work if the
> procedure is exported.
>
> If the procedure is local to the module, you have to use this technique
> to call it with a different prototype.
>
> D myproc           pr
> D   ... parms ...
>
> D myproc_reset     pr            extproc(myproc_procptr)
> D myproc_procptr   s          *  procptr inz(%paddr(myproc))
>
>
> --

Something strange I've noticed about pointer based procedures and EXPORT.

I have a program that, instead of using compile time, top down logic (nested
if/then/else structures) uses run time bottom up logic (state machine).

 *
 * ... pointer based procedures ...
 *
d procProxy       pr              *   ProcPtr ExtProc(procProxy@)

 *
 * ... standalone variables ...
 *
d procProxy@      s               *   ProcPtr
d seed            s                   Like(pmSeed) Inz(0)

 *
 *                            Mainline
 *

 /free
  *InLR = *On;

  procProxy@ = init(seed);
  DoU ( procProxy@ = *NULL );
     procProxy@ = procProxy();
  EndDo;

  eoj();
  Return;

  BegSR *INZSR;
   //
   // seed for random number generator
   //
   If ( %PARMS >= 1 );
      seed = pmSeed;
   EndIf;
  EndSR;
 /end-free

This program is bound to a module containing:

init()
eoj()
reset() (possibly)
plus one or more unknown procedures.


The init routine returns the pointer of the first procedure
to be executed. Every executed procedure returns a pointer to the
next procedure to be executed (or *NULL upon end of job).

What I find curious is that the only procedures that have
to be exported are init() and eoj(); I can execute the private
procedures (through a pointer based procedure) if I know
their addresses.

I like this; I can table drive my logic at run time.

Chris
--
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