Re: Storing data and code in a Db with LISP-like interface

From: J M Davitt <jdavitt_at_aeneas.net>
Date: Fri, 05 May 2006 04:38:56 GMT
Message-ID: <AFA6g.31467$P2.17781_at_tornado.ohiordc.rr.com>


Bob Badour wrote:
> Dmitry A. Kazakov wrote:
>

>> On Thu, 04 May 2006 15:12:02 GMT, Bob Badour wrote:
>>
>>> Dmitry A. Kazakov wrote:
>>>
>>>> On Tue, 02 May 2006 17:58:44 GMT, Bob Badour wrote:
>>>>

[snip]

>>>>> A supertype is a superset of values
>>>>
>>>>
>>>> This is a common misconception. The domain set of a supertype is not a
>>>> subset of the domain set of its subtype.
>>>
>>>
>>> No, it is a superset. I thought I was clear on that.
>>
>>
>> OK, you share that misconception.

>
>
> It is not a misconception. All the values of a subtype are necessarily
> values of the supertype. This makes the supertype a superset of values.
> All of the operations that apply to values of a supertype also apply to
> values of the subtype. This makes the supertype have a subset of
> operations.
>
> Any type theory that gets the above wrong is for shit.
>
>>>>> and a subset of operations.

What Bob said... is completely correct. I'm absolutely amazed that there's so much affection for the flat earth era beliefs. The theory Bob refers to is so simple and effective that I find myself wondering, "Why are otherwise sharp people spending so much energy propping-up those obviously broken, half-a-solution, incoherent inheritance models the OO crowd is so fond of?"

If we are applying mathematics,
>>> then quite clearly a supertype is a superset of values and a subset >>> of operations.

Very succinct. Very correct. Very simple. I suspect many readers will miss the subtle but significant use of the words "values" and "operations" and will, instead, think "variables" and "methods." They ain't the same.

[snip]

>> It is an application of and for the ad-hoc shit. Scatology is a science,

>
>
> Exactly! And that describes OO to perfection.
Received on Fri May 05 2006 - 06:38:56 CEST

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