Re: just curious - Number of Parms

[jpcarr@xxxxxxxxxxxx]

Gary,

You are right as far as you went.  I have been using Externally defined
D/S's since 1984 on the Sys/38 and you know
we didn't have Procedures till just now.  I said "When I use parameter
lists" . When I am coding Procs, I don't,  just for the reason you said.

However, I was talking with Phil Coulhard about this old technique, and
then the subject turned to PCML.  Which is really where I was trying to go
with Externally Defined D/S's as the interface definition. To externalize
it from the program.  To me the bigger sin(being a data base bigot) is
using a 15,5 parameter variable for (say) a customer number or invoice
number when my data dictionary defines it as 7,0.    I want that attribute
of the DB customer entity to cascade everywhere I used customer number.  In
every file,(PF,DSP,PRTF) AND ALSO in program to program interface
definitions!!  Hence the attempt to root the definition of variable
definition in my data dictionary.

BTW, this helped tremendously during Y2k.  Since our interface were
structures(defined with PF's)  we knew EVERY place a date was being passed
as a parameter!

But passing a zoned variable and the receiving proc, seeing it as Packed
(or date from *USA and the proc seeing it as *ISO)  along with compile time
verification is a good thing.

Well I'm rambling again, But you and I are on the same side with this one
Gary.  We both want a well defined, verifiable function to function
interface definition.

BTW,  what does everyone thing of the possibilities of PCML to help in this
area???

Respectfully
John Carr

------------------
Ah, but there are excellent reasons to pass individual parameters. With
procedural RPG, you have parameter validation that occurs before
run-time (nice to avoid those failures). Additionally, use of a data
structure removes considerable flexibility. You can no longer take
advantage of those situations that allow you to do such things as pass
numeric parameters without worrying whether it is packed, zoned, ...

Of course, there are circumstances in which passing a data structure as
a parameter is indeed appropriate. However, I don't feel that using one
to avoid passing individual parameters qualifies as one of those
circumstances.


Gary Guthrie
REAL Solutions Technical Support
NEWS/400 Technical Editor

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