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From: Robert A Duff <bobduff@world.std.com>
Subject: Re: OS Bindings (was: Where is the elusive jump command?)
Date: 2000/04/12
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Sender: bobduff@world.std.com (Robert A Duff)
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Organization: The World Public Access UNIX, Brookline, MA
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Date: 2000-04-12T00:00:00+00:00
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Robert Dewar <robert_dewar@my-deja.com> writes:

> OK, but this really has nothing to do with type checking, which
> is why I was confused by your original post. But if you want
> this kind of range checking, then of course do NOT use a modular
> type to model the C type.

One problem is that I can't follow that advice in the case of the
largest supported integer.  That is, I can't say:

    type T is range 0..2**64-1;

so I have to use a modular type.

Unsigned types are often used in C when modular arithmetic is *not*
desired -- the desire is for non-negative numbers, and unsigned gives a
wider range of them (avoids wasting a bit).

- Bob