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Date: Fri, 26 Sep 2014 09:58:59 -0700 (PDT)
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Subject: Re: Integers and Mathematical Correctness
From: AdaMagica <christ-usch.grein@t-online.de>
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Date: 2014-09-26T09:58:59-07:00
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On Friday, September 26, 2014 6:38:10 PM UTC+2, Niklas Holsti wrote:

> False. Ada can overload operators on the result type, so you can very 
> well add
>
>    function "/" (Left, Right : Integer) return Rational;
>
> and have both"/" visible and used with in-fix notation.

Nah, it's not that easy. The reason is that Integer is defined in Standard, which always has precedence for any use-clause.

You need a separate integer type

  type Whole is range ...
  function "/" (Left, Right: Whole) return Rational;

There is a complete implementation in
http://www.christ-usch-grein.homepage.t-online.de/Ada/Dimension/SI.html
with Text_IO, Image and Value; appropriate test units exist also.

GNAT had much fun with overload resolution - it took very long until it could deal with my rational numbers.