Re: Will RPG eve become an object-oriented language?

[Chris Pando <chris.pando@xxxxxxxxx>]

I've been doing something similar since ILE and *SRVPGMs. A class is
nothing but two sets: a set of data structure definitions, and a set of
procedures (methods) which can operate upon them. An object is nothing but
a pointer to memory. You need a constructor (new()) and a deconstructor.
That doesn't give us all the syntactic sugar, or things like inheritance
built-in, but I don't spend a lot of time inheriting. It does give us a '
black box' which hides implementation details.
ILE/RPG isn't object oriented, but it is certainly possible to write code
that is heavily heavily oop flavored.

On Tue, Mar 14, 2023, 1:05 PM Nathan Andelin <nandelin@xxxxxxxxx> wrote:

> I asked Barbara Moris 20+ years ago if ILE RPG might ever become an
> object-oriented language. At that time she indicated that it was a subject
> of debate within IBM.
>
> She however suggested that I might enjoy writing service programs which
> exported procedures pertaining to objects, including a procedure for
> instantiating new objects. The "new()" procedure would use %alloc() to
> return a pointer to a data structure, which contained all the object
> properties (data-structure sub-fields).
>
> For example, if the "object" were a "stream file", you might instantiate a
> stream file using a procedure named perhaps stmfNew(), which would return a
> pointer to a data structure instantiated via %alloc(). Internally, I might
> name that data structure "stmf", and include all its attributes, such as
> the IFS file name pertaining to it.
>
> After writing a "new()" procedure, write other procedures which include a
> parameter for passing an "object" reference, which would be the pointer to
> that allocated data structure.
>
> Bottom line is that while ILE RPG may not have all the characteristics of
> an OO language, you as a programmer can do OO things with ILE RPG, if you
> like that approach.
>
> Every time a new() procedure is called, I store the pointer returned from
> %alloc() in an internal linked list, which provides a means of deallocating
> any data structures that may have been instantiated during the use of the
> service program.
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