Re: Procedure pointers - can I do this??

On 18/12/2004, at 7:05 AM, Larry wrote:

That's an interesting idea. I'd find it scary if it worked. Personally, I'd
rather use getter methods to retrieve variable data across module
boundaries. My reasoning is that, as RPG only really has two access
modifiers - PUBLIC (exported) and PRIVATE (not exported), you can't have
"package" or "protected" access to your own data. Thus, if you export a
variable from one of your modules you are allowing it to be modified by ANY
client program that binds to your service program.

You may want some of your
own programs access to the data, but not ANY program. The only safe way to
allow "restricted" access is to encapsulate the data through sub-procs. The
sub-proc can then perform some form of validation prior to returning the
variable data. The other beauty of encapsulation is that you can modify HOW
you generate the data internally, and return different values in different
scenarios. By laying bare your internal variables you restrict your ability
to re-design your module code.

Regards,
Simon Coulter.
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