RE: "guessing" the parameter type.

["Steve Richter" <srichter@xxxxxxxxxxxxx>]

what about a data pointer?

The MI func ref says the SETDP ( set data pointer ) instruction is
accessible via bound program built in number 388 ( whatever that means ).
And MATPTR is built in nbr 89.

The way a data pointer works is that the 16 byte pointer contains both the
addr and scalar attributes of what it points to.  To retrieve the
attributes, run the MATPTR instruction. To set the data pointer, use SETDP.

Maybe now that IBM has lost interest in ILE as a grand scheme in favor of
the JVM ( guessing ), the iSeries people can start adding iSeries only
enhancements to ILE. Bringing back the data pointer and the genius who
designed it would make the system better.

-Steve


-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx]On Behalf Of Jon Paris
Sent: Sunday, August 24, 2003 1:41 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: RE:"guessing" the parameter type.


 >> Im really aware that i can't get that info from the pointer itself (a
pointer is just a pointer anyway), but i was wondering if using the address
of the data could I get the data type somehow.

No, you can't.  The compiler does not store this information because it does
not care.  The data type/size information is used by the compiler to
determine what code should be generated, it has no value beyond that point.

As I and others have pointed out, two completely different pieces of data
can have the same address - that address alone could therefore _never_ be
enough.  That's why operational descriptors were introduced as part of ILE.
Unfortunately they were never fully implemented and so we have no mechanism
on the system to do what you want, whether we use just the pointer or
descriptors.

Jon Paris
Partner400
www.Partner400.com


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