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From: Harald Korneliussen <vintermann@gmail.com>
Newsgroups: comp.lang.ada
Subject: Re: not null
Date: Fri, 6 Mar 2009 04:01:45 -0800 (PST)
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Date: 2009-03-06T04:01:45-08:00
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On Mar 4, 5:09=A0pm, Adam Beneschan <a...@irvine.com> wrote:

> I'm having difficulty understanding the point. =A0You have to have the
> idea of the lack of a reference. =A0How else would you implement a
> linked list abstraction?

You can use algebraic data types to do that in a type safe manner.
Haskell, Ocaml and many smaller functional languages do: If a function
returns a "Maybe Integer" type, the compiler will warn you if you
pretend it's an Integer without dealing with the "Nothing" case.