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!news.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: Haskell, anyone?
Date: Mon, 16 Nov 2015 08:45:32 +0000
Organization: A noiseless patient Spider
Message-ID: <lyegfqib83.fsf@pushface.org>
References: <c6ac0d2f-52af-4aa6-ba6f-34f61e3c93e8@googlegroups.com>
	<dd1ada14-493d-44fc-a081-3a69515f2702@googlegroups.com>
	<n2b23f$aom$1@speranza.aioe.org> <87mvue50ey.fsf@ixod.org>
	<87d1vaoa6y.fsf@nightsong.com> <n2bosk$gsq$1@speranza.aioe.org>
Mime-Version: 1.0
Content-Type: text/plain
Injection-Info: mx02.eternal-september.org;
 posting-host="29a2b57997615acde1fccc73c72adb9b";
	logging-data="29937"; mail-complaints-to="abuse@eternal-september.org";
	posting-account="U2FsdGVkX19d/pokHEMCnLRI2KZ8SYjZP/uTMBE0uug="
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (darwin)
Cancel-Lock: sha1:QNRoSCIHYyzbrBoGRUkBi5SF3z8=
	sha1:8dxVbVRMIuXIUUqccv0hSeIfEkU=
Xref: news.eternal-september.org comp.lang.ada:28393
Date: 2015-11-16T08:45:32+00:00
List-Id: <comp.lang.ada>

"Nasser M. Abbasi" <nma@12000.org> writes:

> with ada.text_io; use ada.text_io;
>  procedure foo is
>    type I is range 0 .. 20;
>    x,y : I :=15;
>    z : I :=0;
>    begin
>      z:= x + y ;
>  end foo;
>
>
>>gnatmake foo.adb
> gcc-4.8 -c foo.adb
> foo.adb:8:12: warning: value not in range of type "I" defined at line 4
> foo.adb:8:12: warning: "Constraint_Error" will be raised at run time

The compiler can only do this because the values and the assignment are
close enough (in the same scope?). How often does this sort of mistake
happen IRL?