Re: Ada vs Delphi?

[aratel@total.net (Andre Ratel)]

On Wed, 11 Aug 1999 16:37:54 GMT, Robert Dewar
<robert_dewar@my-deja.com> wrote:

>You definitely do NOT understand, which is not surprising since,
>as I expected, Delphi is not strongly typed in this area.

The Delphi books I have say that it is strongly typed (but, of
course, they compare it to C :-).

>Your view of types above is strictly structural, you declare
>things to be signed or unsigned according to their value range
>and then worry about mixing these values.
>
>That has nothing at all to do with the kind of strong typing
>we are talking about, where you have:
>
>  type minutes is range 0 .. 59;
>  type seconds is range 0 .. 59;
>
>  mm : m;
>  ss : s;

I suppose, here, you meant
  mm: minutes;
  ss: seconds;

>Now mm and ss have IDENTICAL representation, but are of quite
>different types, so an assignment
>
>  mm := ss;
>
>which is almost *certainly* a bug, is statically illegal, just
>as illegal in fact as trying to assign a record to an integer.

OK. I'm putting all the pieces together now. And I suppose
that if mm and ss are related and you need to combine them
in a single expression, you would proceed through typecasting.
For example, 

  type minutes is range 0 .. 59;
  type seconds is range 0 .. 59;
  type count is range 0..3600;

  mm : minutes;
  ss : seconds;
  cc: count;

  cc:= 60*count(mm) + count(ss);

But how do you avoid complex expressions becoming cumbersome?


	Andre