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From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: SI Units Checked and Unchecked
Date: Thu, 9 Aug 2018 18:07:23 +0200
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Xref: reader02.eternal-september.org comp.lang.ada:54111
Date: 2018-08-09T18:07:23+02:00
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On 08/09/2018 02:44 PM, AdaMagica wrote:
> 
> The base type is private:
> 
>    type Item is private;
> 
> There are subtypes defined for all 7 base units defined in the SI system and many more:
> 
>    subtype Length is Item with Dynamic_Predicate => has_Dimension (Length, "m");
>    subtype Volume is Item with Dynamic_Predicate => has_Dimension (Volume, "m**3");
>    subtype Speed  is Item with Dynamic_Predicate => has_Dimension (Speed , "m/s");
>    subtype Force  is Item with Dynamic_Predicate => has_Dimension (Force , "N");
>    subtype Resistance is Item with Dynamic_Predicate => has_Dimension (Resistance, "Ohm");
> 
> Variables are defined like this:
> 
>    A: Acceleration := 5.0*"m/s**2";
>    V: Speed := 10.0*"km/h";
>    T: Time  :=  1.0*"min";
>    D: Length := V*T + 0.5*A*T**2;

Is this standard Ada 12, or is it GNAT specific?

-- 
Jeff Carter
"I was in love with a beautiful blonde once, dear.
She drove me to drink. That's the one thing I'm
indebted to her for."
Never Give a Sucker an Even Break
109