RE: Passing Multi-Occurence Data Structures

Hi Buck, et.al. -

It's an interesting design question.  If you pass a pointer to a global
MODS, then in reality you can simply omit the pointer and have the
subprocedure directly manipulate the MODS.  On the other hand, having a
pointer in the parameter list shows your intent to use the data structure in
the subprocedure.  I think I would pass the pointer.

I agree with passing the pointer and using a local MODS based on that
pointer.  Among other things, it allows the procedure to be put into a
service program or different module without requiring any changes, as long
as everything else in the procedure also is passed.

The one gotcha to watch for: %addr(MODS) passes a pointer to the CURRENT
occurrence of the MODS.  So if the procedure wants to use all of the
occurrences in the MODS, rather than just one, you need to set the current
occurrence to the first occurrence before calling the procedure.  Another
option would be to initialize a pointer to the beginning of the MODS and
just pass that pointer all of the time instead of using %ADDR.

(Can you guess how I know about this?  <G>)

Ken
Opinions expressed are my own and do not necessarily represent the views of
my employer or anyone in their right mind.