Re: No exceptions?

From: J M Davitt <>
Date: Thu, 29 Jun 2006 21:07:49 GMT
Message-ID: <FiXog.1332$>

paul c wrote:
> J M Davitt wrote:

>> paul c wrote:
>>> Bob Badour wrote:
>>> ...
>>>> The way to avoid exceptions is to treat them as compile-time errors.
>>> I take it you really mean "ONE way to avoid exceptions ...".  For one 
>>> thing, I am interested in being able to express "x join y" in advance 
>>> of defining a header for "x" (and I would like to evaluate it as well 
>>> if that is logically possible!).
>>> p
>> This has me scratching my head.  Without a heading, there can be no
>> parameters.  Without parameters, there can be no arguments.  Without
>> arguments, there can be no quantifiable proposition.  Which leads me
>> to, "A relation without a predicate is...  What?"  I find this
>> especially curious because you mention the Closed World Assumption
>> in the same post.  (Don't forget the Excluded Middle!)
>> So, Paul, what are you trying to explore?

> Maybe instead of saying "defining a header", I should have said "in
> advance of entering a header". I had in mind that an "empty" header
> would be assumed.

Empty heading: like DEE and DUM have empty headings?

> My peculiar view doesn't require me to ask "what is the predicate of
> such and such a relation". This will sound ridiculous to most people I
> think because one would ask "well, what good is a database whose
> predicates we don't know?". OTOH, one aspect that for me defines a
> relational engine is precisely that it must not circumscribe even in the
> most indirect of ways what predicate a particular relation has, its
> whole value is in being to manipulate relations without knowing that -
> otherwise it would be an application!

Well, in that regard, it's already done -- in DEE ad DUM, no? And I think it's correct - but somewhat confusing - if you want other names for those relation values.

It almost seems as though you want to declare an analogue for DUM, syntax-check some expressions, and add attributes to your relation with the confidence that your expressions are still correct.

> Apologies if this is metaphysical mumbo-jumbo. Will ponder the CWA and
> excluded middle again.
> p
Received on Thu Jun 29 2006 - 23:07:49 CEST

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