Re: c.d.theory glossary -- definition of "class"

From: mAsterdam <mAsterdam_at_vrijdag.org>
Date: Sat, 26 Jun 2004 14:47:18 +0200
Message-ID: <40dd7052$0$65124$e4fe514c@news.xs4all.nl>

x wrote:

> mAsterdam wrote:

>>Dawn M. Wolthuis wrote:
>>>mAsterdam wrote:
>>>
>>>>Glossary 0.0.4:
>><snip>
>>>>[Class]
>>>>A class is what provides a name and a place for
>>>>the abstract behavior of a set of objects
>>>>said to belong to the class. (Larry Wall, Apocalypse 12)
>>>>
>>>>note:
>>>>Other definitons welcome, this goes for the rest as well,
>>>>of course.
>>>>
>>>>Some use 'class' as having exposed data.
>>>>Please be explicit about this if you do so.

>
> [Object] - The embodiment in software of an automaton. The software brick.
> - an identity (sometime independent of location) -
> instead of an address
> - a variable state (sometime independent of location) - instead
> of a (memory) location
> - methods (behavior) (sometime independent of location) - instead of
> monolithic code.
> - messages (input/output) (sometime independent of location) - instead of
> rigid flow of control/data.

There must be a point here somewhere, but it is hard to extract. I have a feeling it tries to explain too much/solve too many issues in one go.

> [Class] - Divide et Impera !
> The size, shape and matter of the bricks.

These would be the properties all objects belonging to the class have in common, ... ('Entity'-like - or Entity-type like if you like^H^H^H^H prefer)

> The physics, the chemistry, ...,
> the philosophy, the society.
> Dictate the rules that objects (in the class) must obey.

and this would focus on behavior.

<snip>

>>A class is about behavior. Is it about data?
>>An object, instance of the class, may have
>>some data, but to get that data we'll have
>>to ask it (by means of what the class told
>>us about how to ask objects of this class questions)
>>to give us that (and maybe other) data.

>
> Well, code is data - remember ? :-)

You have to change view to see the
'code'-ness and 'data'-ness of the same signs.

> A class is about computer software components. :-)

Yep. So are package, module, source-file, library. Maybe some fidgeting with (some of) these terms can help us come up with a more clarifying text. Received on Sat Jun 26 2004 - 07:47:18 CDT