Re: Can RPGLE simulate OO programming?

I was just thinking... Perhaps you could have a service program per file and
as the first parm you would pass the operation and as the second parm a
pointer to a DS and optionally a third parameter also a parm to a DS. The DS
could be allocated dynamically by either the service program or the
application but then you would be able to have arrays of objects and perform
the action upon it via the parameter interface.


My father used to say that any computer problem can be solved by throwing
another level of indirection at it :-)

Say you had a service program Called InvItem.
This service program would support the following operations.
New - This would allocate storage and return a pointer for the DS.

Free - This would free the storage for the pointer passed in.

Output - This would write the data from the DS to the datafile (either
update or insert) This would have both pointer parms capable of being used
or just the first. If you just used the first then you could potentially
blast an existing record out of the water... This is ok sometimes.

Write - This would only write the data from the DS to the data file (insert
only) Would only use first pointer.

Update - This would only update the data from the record. This would use
both pointers to Data structures the first being the one that was returned
to you and the second being the one where you had made changes.

Delete - This would attempt to delete the record for the associated values
in the data structure. Note SQL could be used for all these database
functions and you would be able to do set at a time operations too.

Get - This would return a record in the second pointer that matched the
criteria in the first pointer.

Next - After a get this would return the next record in the same place.

Previous - After a get this would return the previous record.

I am sure that there could be a lot of fun for someone in this :-) It would
give us a sort of OO way of doing things.

What do you all think?
Eric


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