Re: Software Architecture/Design

> Tom Plunket wrote:
>>
>> Anyway- this is a very strange discussion to me, having been steeped
>> in writing OO code in C, since obviously "the data knows nothing" and
>> all of the transformations were functions that took an "object" and
>> did some operation with it.

Richard Fabian wrote:
>
> Sorry, forgot to comment on this bit earlier.
> In my experience/understanding of OO, an object class is both a data
> definition and the implementation of the methods that can be called on it.
> An object instance is a self aware data construct.
> From this definition, the closest you can approach dumb data is persisting
> the type of the object somewhere other than the object's memory. It's still
> object oriented, but code is branching on some other data store.
> In your OO code in C, either your data did know something (i.e. it had a
> type persisted somewhere that branched code dependent on the object) or it
> wasn't object oriented.

This is an interesting point and reframes the discussion somewhat.
It's not about what operations are available on a bit of data, it's
about making decisions about what operations to execute on the set of
data.  In otherwords, is the decision making done based on the
inspection of the data being processed, or is that decision being made
elsewhere?

For this whole stream processing sub-thread, clearly there is no
decision making going on when the data is being processed.  The code
is (ideally) not looking at the individual bytes and deciding what to
do with the data, it's just ripping through the data doing the same
transform on every "element," i.e. it's doing some operation on some
data with a given stride.

I still don't believe that it's an either/or question though.  From my
earlier example, you have a bunch of Cars that each have as a
components an Engine.  When processing an individual Car you're not
going to reach into the injectors and squirt fuel into the cylinder,
but that doesn't mean that you can't inspect specific Engines for some
reason if it becomes necessary.  Arranging your data for "stream
processing" does not require that you can't access individual entries.
 Indeed- an "abstraction" of CarList or EngineList seems superfluous;
you want things that operate on the chunk of data in one go, but you
don't want a "heavyweight" object with lots of manipulators.  Your
bulk/primary processing is still going to be on single elements, the
big change is that that processing doesn't make decisions per entry.
That processing just does the transform on every item.

-tom!

--
_______________________________________________
Sweng-Gamedev mailing list
[email protected]
http://lists.midnightryder.com/listinfo.cgi/sweng-gamedev-midnightryder.com