Re: Windows Ada database support.

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Fri, 10 Dec 2004 14:28:52 +0000 (UTC), Georg Bauhaus wrote:

> Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
>:>:> However, an object's type cannot reflect this, because types
>:>:> are static.  You could associate one different type with each possible
>:>:> combination of component values in your program...
>:>: 
>:>: 1. No application uses all possible combinations. They have very concrete
>:>: things to do.
>:> 
>:> For example, they react to different value that an object has in time?
>: 
>: Where is any problem? Doesn't sin(x) react to any value of x whenever it be
>: called?
> 
> if sin(x) > threshold then
>  ...
> 
> That is, a program doesn't express all possible flows in the set of type
> declarations.
> Similarly, when programs construct values from standardised "garbage
> databases", they express some flows using query results, not necessarily
> a style of writing close to the type system.

Nobody requires to express all semantics in type relations. [Yet compare
how "relationists" are trying to force semantics into relations!]

The known to be stable part of the semantics should be mapped into types.
That is the stand point of strongly, manifestly typed languages like Ada.
Because for practically any application, there is such stable part, and it
is reasonable large. If you will try to convince me that business
applications cannot be programmed in that way, then well, we should agree
that we disagree.

> Moreover, future behavior of the program will be influenced
> by manipulating the "garbage database". This feels somewhat like symbol
> manipulation  ;-)

This is just plainly wrong design. Note that even Ada compiler need not to
translate itself together with the program code. The very fact that Ada
compilers were successfully written in Ada shows that strong typing is no
obstacle.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de