Re: Objects and Relations

From: Marshall <marshall.spight_at_gmail.com>
Date: 23 Feb 2007 19:12:26 -0800
Message-ID: <1172286746.498835.185020_at_k78g2000cwa.googlegroups.com>


On Feb 23, 6:40 pm, "David BL" <davi..._at_iinet.net.au> wrote:
>
> You did not realise my point? I'm talking about representing these
> things and processing these things, and not merely stating facts
> *about* these things. My whole point has been that RM is perfect for
> the latter but not so good for the former. If you agree with that
> then please say so.

I don't, and as near as I can tell no one else here does either.

 > If you think RM is suitable for scenegraphs I would be particularly
> interested.

That is a strange way to think about it. On the one hand you have a collection type and on the other hand you have application level constructs. Let's invert it:

  If you think hashtables are suitable for payroll I would   be particularly interested.

Doesn't make much sense.

(Note that this is *structurally* similar to what you wrote, but not semantically similar.)

If you want to compare apples to apples, the thing to compare relations with is other data structures. Compare relations with C++ objects. Or with any of various things you'd find in the STL. Compare them in terms of what operations you'd like to perform, as well as what you'd like to model.

I did this a while back for two Java stalwarts, Hashtable and ArrayList. It was immediately clear that none of the methods on those classes were worthy of making into an abstraction; they were all trivially accomplished with RA operations.

Marshall Received on Sat Feb 24 2007 - 04:12:26 CET

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