Re: Strategic Java Usage/Productivity -- JAVA400-L

Nathan,

in my opinion rpg is very limited to "emulate" or even implement OO; I agree 
that you can write better code with some technics, you mentioned, but java is 
much more productiv in this.

some details I would not agree:

> There are more similarities between ILE and OO languages than most people
> realize.  For object instantiation in RPG:
>
>  Eval myInstance = myClass_New(parameters)
>
>  Callp myClass_doSomething(myInstance: parameters)
>
> Where myInstance would be a pointer to a data structure containing instance
> properties, which would be referenced from myClass procedure calls.

The problem here is: you have no qualified naming for referencing methods and 
you can't have more than one instance of a rpg programm. For example: I have 
a rpg implementation of a HashTable (available at my german Freeware page), 
but you can't have two of them in one program!

>
> For inheritance in RPG, create a new module, either importing and wrapping
> the procedures in a base module, or create a new module containing just
> procedure overrides, then bind to both modules.

That's by far not the same, even if you avoid static binding at compiletime. 
You can't make generic changes as in java and you have 10 times mor code.

>
> For polymorphism in RPG, define data exports in modules, supplementing
> procedure interfaces, which alter the behavior of procedures based on data
> content.

That's not polyymorphism, maybe you are thinking of overloading of methods, 
but this would not be as readable as in java.


>
> It's true that most RPG programmers wouldn't consider following OO design
> patterns, unless they first immersed themselves in OO languages for a
> period of years.  But I returned to RPG for both performance as well as
> productivity reasons.

There are nearly none open source components in rpg available and I don't know 
where you get the better productivity in rpg from??? 
I agree with you, that writing well modularuized code in rpg enhances rpg 
programming productivity, but writing java is faster, if you use available 
components.


Dieter 
>
> Nathan.
>
>
> ----------------------------------------------------------------------
>
> message: 1
> date: Wed, 17 Mar 2004 11:11:23 -0800
> from: "Paul Holm" <pholm@xxxxxxxxxxxxxxxxx>
> subject: Strategic Java Usage/Productivity
>
> Nathan/All
>
> Thanks for the clarification of your points.
>
>  The point I was trying to make is that Java and its OO capability can lead
> to much much higher levels of productivity than procedural and RPG
> languages in both utilities and application development projects.  I am not
> an RPG expert so I might be missing something(s), please excuse/correct me
> if I'm off.  The flexibility and productivity possible via inheritance,
> polymorphism, frameworks, and interfaces would be very difficult or
> impossible to match with procedural languages.
>
> I agree that performance can be an issue with complex objects but that all
> depends on the object/framework design in my experience.  Frameworks and
> components; that's where I enjoy spending most of my time, especially since
> I can't afford to golf daily which is my other passion</sigh>.  Inquiry
> objects with inherited "maintenance" method for insert, update, delete,
> copy can carry minimal overhead and the payback is huge in terms of
> programmer productivity.
>
> For example, I built and deployed, an additional inquiry operation which
> returns a completely generic Java component with inherited but overridable
> maintenance methods (insert, update, delete, copy) and it performs very
> well.  This "department" inquiry was developed and deployed in 45 seconds
> using  a set of Java components.  That's where I think AS400 shops and
> others can benefit from OO and Java technology.
>
> http://www.planetjavainc.com/wow60/runApp?id=298
>
> Java methods are attached to the class so even multiple instances of the
> components have much less overhead than people suspect.  For example, in
> addition to the inherited maintenance methods, the framework/component also
> inherits:  MS EXCEL, XML, web services, dynamic field level security and
> validation, dynamic associations for linking files to other files, column
> level sorting (black triangles), dynamic column headers, and several other
> features.  All features inherited, customizable, to any database, on any
> platform with zero programming effort needed; all in 45 seconds.
>
> That's what Java and OO/frameworks can provide.
>
> As far as the XML to HTML performance,  I haven't worked with it too much
> but I imagine having to parse and regenerate the UI on the fly could be
> expensive;  I don't know enough about that to comment.  Have a good ne.
> -Paul Holm
>
>
>
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-- 
mfG

Dieter Bender


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