Re: OO Design induces an existential crisis

AndyW wrote:
> On 29 Jul 2005 04:08:57 -0700, hansewetz@xxxxxxxxxxx wrote:
>
> >AndyW wrote:
> >> On 27 Jul 2005 06:27:19 -0700, hansewetz@xxxxxxxxxxx wrote:
> >>
> >> >AndyW wrote:
> >> >> On Sun, 10 Jul 2005 10:49:01 +0200, "Ilja Preuß" <it@xxxxxxxxxxxxx>
> >> >> wrote:
> >> >>
> >> >> >AndyW wrote:
> >> >
> >> >> Identity: Coffee cup.
> >> >
> >> >> This is a mind boggler - because in purism the cup only has one state
> >> >> and that is that it exists. This is the state apart from the one
> >> >> implied by its intended usage. Currently the one on my desk merely
> >> >> exists since its not being interacted with.
> >> >
> >> >This idea of 'purism' sounds like pure nonsense. When you model a
> >> >problem, using OO or non OO methods, you base your model on your
> >> >perception of the world. Depending on the context and your objective
> >> >you will model your cup in different ways.
> >> >
> >> I suspect that you missed the very first post in the thread that sets
> >> out the model being used in the rest of the thread.
> >>
> >> If you had read it, then it sets out that there are different
> >> techniques used when modeling pure object, abstractions, services and
> >> mixins. The main technique is to understand what each is and learn
> >> to recognise them, then use the appropriate technique to model them.
> >
> >I have started to believe that this discussion is not so useless after
> >all. However, it is not because of the content it is useful but because
> >of its lack of content. It many ways it is a poster child for some
> >other discussions on the newsgroup.
> >
> >You are stating some ideas about how to model problems/solutions using
> >objects, abstractions etc. What is missing is a 'description' off
> >what these things are. I admit you supply a half baked description
> >based on 'tangibility' that does not hold up after a few seconds
> >scrutiny. Your ideas also lack an 'explanation' for why they should
> >work, i.e., help in building better software.
>
> Really.
>
> Actually, i'm using an extension of the Booch model (identity, state
> and actions). Its been extended with tangibility to define the
> difference between an object, service and mixin (the latter two are
> not tangible).
>
> services and mixins come from the taligent object model. They are
> used to classify two different types of entity - something that is
> data only and something that only has functions (and no data).
>
> This concept is also used heavily in most Framework descriptions and I
> suspect in many patterns books.
>
> It is based on both the fundemental rules of classical OO and also the
> fundemantal rules of human cognition.

You still have not answered questions such as:
- How does tangibility help when you model for the
purpose of building software?
- What is a 'pure' object?
- What counts as something tangible?
Does a spoken word count as tangible - the air
vibrations do touch the eardrums, i.e. is tangible.
- Is something that did exist at one time tangible,
i.e. an object in your view of the world? Melt your
favorite coffee cup and then describe the coffee cup
before it was melted. Are you describing an 'object'
or an 'abstraction'?
- Is something that will exist in the future an object?
A house not yet built; do you model it as an object?
For sure it is not tangible now.
- Is the sun an object, i.e., is it tangible?
What about an electron or a photon?

You state in a previous posting:

>> Once you look at the object in its purity you are no longer being
>> confused by actions/behaviour that are not directly part of the object
>> itself. For example, you wont be confused between the
>> actions/behaviour of a cup vs that of a tea cup.

Are you stating that there is some intrinsic property of a cup that
magically turns it into a tea cup? Also, where do you draw the line
that separates what is part of an object and what is not? Do you take
the subatomic structure into account in your 'pure' teacup object?

It seems as if you don't take a context and an objective into account
when you model an 'object'. Is this correct? If so, you ideas are
pure nonsense. An observer of something will always focus on certain
aspects of the thing being observed. In general, the purpose of
something is a relation between the 'something' and an observer.
The purpose is not an absolute; it is relative to the observer. If you
could take everything into account when you describe something you
would be what many people call 'God'. Myself being a mere mortal, I
realize that a cup becomes a 'teacup' when the tea starts pouring
into it.

Regards,
Hans Ewetz

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