Re: Time to get serious

On Fri, 25 Feb 2005 15:17:58 -0600 (CST), Scott Klement
<midrange-l@xxxxxxxxxxxxxxxx> wrote:
> 
> 
> > What about something simple like address book functionality?  Vendors,
> > Customers, and Employees all have the same core requirements of a name
> > and address.  In an OO language you would write the address book
> > object once, then drop it in as a base struct in the vendor, customer
> > and employee data struct.   You cant do that in RPG ( or ILE ).
> 
> Why can't you?  I can code the following in RPG, isn't that what you're
> talking about?
> 
>      D Address_T       ds                  qualified
>      D   Street                      30A
>      D   City                        13A
>      D   State                        2A
>      D   ZipCode                     10A
> 
>      D Vendor          ds
>      D   Account#                     4S 0
>      D   Terms                        3A
>      D   Contact                     30A
>      D   RemitAddr                         likeds(Address_t)
>      D   SalesAddr                         likeds(Address_t)
>      D   SupportAddr                       likeds(address_t)

that is true.  If I had v5r3 on my system I would make great use of
sub field data structs.    If the compiler was open sourced, struct
member procedures would be the first feature I would add.

To print an address label for the Vendor struct the programmer should
be able to code the following:
   vendor.PrintLabel( ) ;

the rpg way of:
   PrintAddressLabel( vendor.RemitAddr ) ;
is too verbose.

after someone from IBM posted the QleActPgmBnd and the QleGetExp api
examples last week I was trying to work out how to implement virtual
functions and interfaces in RPG and ILE.  It was an interesting
exercise. If you over allocate the space for your struct and place a
pointer to a vtable in the extra space you can start to implement some
virtual class features.   But using just RPG it gets messy very
quickly!

-Steve