Re: Operators -> unit analysis

["Matthew Heaney" <mheaney@banet.net>]

In article <387383D0.4EA02E95@earthlink.net> , Charles Hixson 
<charleshixsn@earthlink.net>  wrote:

> And some good way to handle units.  So that we could safely say things like:
>
>      speed := 37.miles / 1.5.hours;
> I'm not too pleased with the syntax, but the idea is there.

You can already do this:

  Speed := Miles'(37.0) / Hours'(1.5);

I always recommend type qualification for literals when units are an
issue.

> I dislike the syntax:
>     speed := (37 * mile) / (1.5 * hour);
> though I prefer it to:
>     speed := miles (37) / hours (1.5);
> but that's the best that I know how to do it in Ada.  Is there a better
> choice?  (I.e. one that would look more like what a math student would write
> in a word problem?)

See above.


> Of course one could say:
>     dist    :    constant Miles    :=    37;
>     time   :    constant Hours    :=   1.5;
>     speed :  MpH;
>     speed    :=    dist / time;
>
> but that seems quite unnecessarily verbose!

Agreed.