Re: Object-relational impedence

From: David Cressey <cressey73_at_verizon.net>
Date: Mon, 17 Mar 2008 11:47:51 GMT
Message-ID: <HTsDj.2221$jw2.1424@trndny04>

"Leslie Sanford" <jabberdabber_at_bitemehotmail.com> wrote in message news:47ddfa17$0$30701$4c368faf_at_roadrunner.com...
>
> "David BL" wrote:
>
> <snip>
>
> > Consider the following three groups of names
> >
> > A: int, double, point, circle, ellipse, square, string, set<int>,
> > tuple, relation
> >
> > B: employee, company, invoice, manager, department
> >
> > C: mutex, textbutton, guiwindow, stack, queue, threadpool,
> > printerproxy
> >
> >
> > Consider these as names for built-in types, structs or classes in a
> > language like C++. I'm characterising the groups as follows
> >
> > A: These are value-types. A value is mathematically well defined,
> > eternal and immutable. A value-type is a set of values plus
> > operations on those values. Variables of a value-type can normally be
> > assigned with any value of that type.
> >
> > B: These are conceptual things that aren't mathematically formalised
> > and typically exist in time and space but are external to the abstract
> > computational machine
> >
> > C: These designate types of objects where object means an identifiable
> > abstract state machine embedded within an overall abstract
> > computational machine. Objects do not generally represent values and
> > do not in general support assignment. Objects always have identity,
> > state and behaviour with respect to the abstract machine. Objects
> > cannot be understood outside the computational machine in which they
> > are defined.
>
> <snip rest>
>
> This was a tour de force post. I enjoyed it quite a bit. Thanks.

I agree. A tour de force. A keeper. My thanks as well. I'm going to reply to one bit of it in a separate reply. Received on Mon Mar 17 2008 - 06:47:51 CDT

Original text of this message