AW: confused over this prototype definition

Fields specified within prototypes are not defined, i.e. are ignored. You
even can move off the fields names within the prototype. The compiler only
checks the data types, length, number of decimal positions, key words and
sequence of the parameters.
In this way MyProcIn and MyProcOut are only defined once!

Mit freundlichen Grüßen / Best regards

Birgitta Hauser

"Shoot for the moon, even if you miss, you'll land among the stars." (Les
Brown)
"If you think education is expensive, try ignorance." (Derek Bok)
"What is worse than training your staff and losing them? Not training them
and keeping them!"

-----Ursprüngliche Nachricht-----
Von: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] Im
Auftrag von David FOXWELL
Gesendet: Tuesday, 12. January 2010 10:56
An: RPG programming on the IBM i / System i
Betreff: confused over this prototype definition

Hi,

I don't fully understand the two DS declarations that follow this prototype
definition. The prototype is in the module source, ie, with all the rest of
the code. The caller uses compiler directives to copy in only the code shown
below. Why does the module compile when MyProcIn and MyProcOut are declared
twice each? Why does the caller need the declarations that follow the
prototype?

Thanks.


D MyProc PR N
D MyProcIn...
D LIKEDS (MyProcInDs)
D CONST
D MyProcOut...
D LIKEDS (MyProcOutDs)

* Input parms.
D MyProcInDs...
D DS BASED (template)
D QUALIFIED

D Parm1 LIKE ( xxxxx )

D Parm2 LIKE ( xxxxx )

* Output parms.
D MyProcOutDs...
D DS BASED (template)
D QUALIFIED

D Parm1 1


* Definition parameters for callers.
D MyProcIn...
D DS LIKEDS (MyProcInDs)
D MyProcOut...
D DS LIKEDS (MyProcOutDs)