RE: Another Idea for Ada 20XX

["Robert C. Leif, Ph.D." <rleif@rleif.com>]

From: Bob Leif
To: Stephen Leake et al.
"Defining _all_ of these required conversion multipliers is the killer
for this concept."

This is particularly true since they are NOT needed! In fact, the actual
combinations of units in physics and chemistry formulas is very large. What
has to be done is a check that the exponents of the units are the same for
addition-subtraction. Of course the data that is an input, an output, or a
check-point must have the exponents of their units being constants.

-----Original Message-----
From: comp.lang.ada-admin@ada.eu.org
[mailto:comp.lang.ada-admin@ada.eu.org]On Behalf Of Stephen Leake
Sent: Monday, December 10, 2001 8:22 AM
To: comp.lang.ada@ada.eu.org
Subject: Re: Another Idea for Ada 20XX


"Nick Roberts" <nickroberts@adaos.worldonline.co.uk> writes:

> "Larry Kilgallen" <Kilgallen@SpamCop.net> wrote in message
> news:C1UHcLPG$dZX@eisner.encompasserve.org...
>
> > > nor to allow 10 minutes * 5 KPH = 833 Meters
> >
> > Are you saying that multiplying two different types (not subtypes
> > of the same type) works in Ada95 ?  My experience is mostly Ada83.
>
> If they are both fixed point types, I think the answer is 'yes', provided
> it's in the context of a specific fixed point type (not universal fixed).
> E.g.:
>
>    D: Distance := Duration(10*60.0) * KPH(5.0);

Umm, surely there must somewhere be defined a "conversion multiplier",
and it must be visible:

function "*" (left : in duration; right : in KPH) return Distance;

otherwise the above statement is not legal, in Ada 83 or 95.

Defining _all_ of these required conversion multipliers is the killer
for this concept.

--
-- Stephe