Re: ILE bug or "feature"?

[bmorris@xxxxxxxxxx]

Barbara Morris wrote:
>> Regarding bug or feature, I don't think it's either.  I think it would
>> be great if the ILE environment could provide something that I don't
>> think is available anywhere else, namely runtime checking of parameters.
>> But the system works the way it works.  The existence of %parms and
>> *PARMS implies that the system won't prevent you from accessing
>> parameters that are not passed; the fact that failure to check %parms
>> sometimes causes a nice pointer-not-set error doesn't mean that problems
>> from not checking %parms are limited to that error.

Then Scott Klement wrote:
>But if that minimal operational descriptor that you mentioned earlier
>isn't being passed, you couldn't actually check %parms anyway, could you?
>
>It sounded to me like it didn't actually know how many parms were passed?

Scott, RPG can't check the %parms value because it might not be
correct.  But if a programmer writes a procedure that expects an to be
able to check %parms, and and the caller doesn't pass an operational
descriptor, it's the programmer's error, one way or another.  (The
documentation for %parms mentions the fact that other languages don't
necessarily pass the OD.)

I think the number-of-parms not always being available is indeed a
performance decision.  I personally think the default should have been
to pass the minimal OD, but by the time RPG got on the ILE scene, the
die was already cast.  (C has a different convention for handling varying
length parameter lists.)

Barbara Morris


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