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From: Niklas Holsti <niklas.holsti@tidorum.invalid>
Newsgroups: comp.lang.ada
Subject: Re: A function that cannot be called?
Date: Thu, 18 Oct 2018 23:57:42 +0300
Organization: Tidorum Ltd
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Xref: reader02.eternal-september.org comp.lang.ada:54638
Date: 2018-10-18T23:57:42+03:00
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On 18-10-18 23:21 , G.B. wrote:
> On 18.10.18 17:33, Stefan.Lucks@uni-weimar.de wrote:
>> On Thu, 18 Oct 2018, G.B. wrote:
>>
>>> There is a type declaration, I rememberd, in Ada, that
>>> does not allow any object of the type to be declared.
>>
>> What, exactly, is the point of your question?
>
> Philip Wadler asked, on occasion[*], whether there was any programming
> language other than Haskell that had a (concrete, usable in the normal
> way I guess) type like ("unihabited") Void in Data.Void.  (The point is
> getting my feet wet at the shores of correspondences of logic, typed
> lambdas,
> and categories with resp. programming languages' features.)

I'm not sure that I understand what you want, but here is a type for 
which no valid and initialized object can exist:

    type Zilch is range 1 .. 0;

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
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