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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Latest suggestion for 202x
Date: Mon, 17 Jun 2019 18:43:28 +0200
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Date: 2019-06-17T18:43:28+02:00
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On 2019-06-17 17:32, Paul Rubin wrote:
> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
>> No, record is not a mapping. A mapping (properly typed) is
>>     f : I -> V
>> where I and V are *types*. You cannot define record members this
>> way. Member names are not 1st class values, member values have
>> different types.
> 
> Each member name is in effect a mapping.  I don't remember the record
> member syntax but something like:
> 
>     type person is record:
>       name : string;
>       age : integer
>     end record
> 
> Then basically "name" is a mapping from person to string, and "age" is a
> mapping from person to integer, and there's some syntax sugar to deal
> with member notation (xyz.name) and assignment (xyz.name := "John").

If Name were an entity in Ada then we could have syntax:

    Name(P)

i.e.

    Name : Person -> String

This would be a mapping. But it is not what Maciej asked, he wanted, I 
suppose, this:

    P(Name)

    P : ? -> ?

instead of P.Name. This is not a mapping of 1st class objects.

He could argue that Ada should follow C++ and use different syntax for 
different names:

    a::b
    a->b
    a.b

To "improve" readability. Why names of an entry, child package, member, 
formal argument of a subprogram etc have all same form A.B. No fun! 
Unicode has 2**24 or so characters free...

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de