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From: Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>
Newsgroups: comp.lang.ada
Subject: Re: Duration vs. Ada.Real_Time
Date: 30 Jan 2001 09:33:38 -0500
Organization: NASA Goddard Space Flight Center
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Date: 2001-01-30T14:46:43+00:00
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Robert Dewar <robert_dewar@my-deja.com> writes:

> In article <3A71E4F6.6D7015AD@acm.org>,
>   Marin David Condic <mcondic.auntie.spam@acm.org> wrote:
> 
> > I would think that a reasonable implementation of Ada for
> > realtime systems would want to insure that the precision had
> > some relationship to the accuracy of the clock available.
> 
> Why do you think that?
> 
> The RM contains no encouragement for this thought!
> 
> Duration is used for other things besides the delay statement.

Perhaps it would be more appropriate for Marin to request that type
Ada.Real_Time.Time_Span (LRM appendix D) match the hardware clock;
that is more clearly intended to be a "hard real-time" clock type.

> And also, programs do various calculations with Duration, if there
> is more precision, these calculations are more accurate.

I agree with Marin here; convert to a type that you know or control
the precision of to do computations.

-- 
-- Stephe