From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!gandalf.srv.welterde.de!news.jacob-sparre.dk!franka.jacob-sparre.dk!pnx.dk!.POSTED.rrsoftware.com!not-for-mail
From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Strings with discriminated records
Date: Wed, 30 May 2018 14:46:08 -0500
Organization: JSA Research & Innovation
Message-ID: <pemv2c$1uq$1@franka.jacob-sparre.dk>
References: <55ce14eb-6b83-4ea0-a550-f9e1410d0b06@googlegroups.com>
 <06a59646-1d72-4200-967b-592ab61c4b1f@googlegroups.com>
Injection-Date: Wed, 30 May 2018 19:46:21 -0000 (UTC)
Injection-Info: franka.jacob-sparre.dk;
 posting-host="rrsoftware.com:24.196.82.226";
	logging-data="2010"; mail-complaints-to="news@jacob-sparre.dk"
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.5931
X-RFC2646: Format=Flowed; Original
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.7246
Xref: reader02.eternal-september.org comp.lang.ada:52788
Date: 2018-05-30T14:46:08-05:00
List-Id: <comp.lang.ada>

"Mehdi Saada" <00120260a@gmail.com> wrote in message 
news:06a59646-1d72-4200-967b-592ab61c4b1f@googlegroups.com...
>>    M : Message := "Hello World";
>
>>Or you could just give string literals to type Message (although you'll 
>>have
> to wait a bit for that capability -- but it should be in Ada 2020 -
> finally).
> I don't get what you mean exactly (meaning of "give"). What would it look 
> like ?
> Would it be something like
> type Message (discriminants or not) is ... end record with IS_LIKE => 
> String ?

See AI12-0249-1. This hasn't been discussed at a meeting yet, so it probably 
will change some, but Tucker suggests aspects "Integer_Literal", 
"Real_Literal", "Null_Literal", and "String_Literal". These represent 
functions that can be specified:

type Message (discriminants or not) is ... end record
    with String_Literal  => Make_Message;

where Make_Message is something like:

    function Make_Message (Lit : in Wide_Wide_String) return Message;

with the obvious semantics when a string literal is encountered.

                                             Randy.