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: 
 border1.nntp.dca3.giganews.com!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!goblin1!goblin.stu.neva.ru!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: What's the cause of extra new line with Text_IO when program exit
Date: Thu, 15 Aug 2013 20:17:46 -0700
Organization: Also freenews.netfront.net; news.tornevall.net
Message-ID: <kuk5kq$e66$1@dont-email.me>
References: <kujtmh$doi$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Fri, 16 Aug 2013 03:17:48 +0000 (UTC)
Injection-Info: mx05.eternal-september.org;
 posting-host="da68e1c0dc00d4aa5d0283c494e3a17a";
 logging-data="14534"; mail-complaints-to="abuse@eternal-september.org";
 posting-account="U2FsdGVkX1/xqpFW1TdipW0xyS/OApz7B0szsHXSlY4="
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
 rv:17.0) Gecko/17.0 Thunderbird/17.0
In-Reply-To: <kujtmh$doi$1@dont-email.me>
Cancel-Lock: sha1:29D4DH77cTqbssjyVQ3zSWVC1Dk=
X-Original-Bytes: 2406
Xref: number.nntp.dca.giganews.com comp.lang.ada:183050
Date: 2013-08-15T20:17:46-07:00
List-Id: <comp.lang.ada>

On 08/15/2013 06:02 PM, Zhu, Qun-Ying wrote:
>
> When executing, they have different behavior.
>
> For hello, you have:
> # ./hello
> Hello World!
> #
>
> While for hello_stream, you got:
> # ./hello_stream
> Hello World!#
>
> If change the last Put to Put_Line for hello, you got the same result.
> I would like to know why it is like that.

Ada.Text_IO writes to a text file of type Ada.Text_IO.File_Type; Hello writes to 
the file Standard_Output. Text files consist of lines of text; lines are 
conceptually terminated by a line terminator. For a version of Unix such as you 
seem to be using, the conceptual terminator is an actual LF character.

While it is not defined by the language what happens to a File_Type when the 
program ends [ARM A.7(6)], it does require that File_Type have finalization [ARM 
A.10.1(86)]. A logical thing for this finalization to do is to make sure that 
the last line is terminated, and it appears that your implementation does this.

A stream is a different creature than a text file, and doesn't know about lines 
or terminators, so it should not be surprising that it adds no terminator.

-- 
Jeff Carter
"It is the German who is so uncourteous to his verbs."
A Scandal in Bohemia
122