From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.5-pre1 (2020-06-20) on
	ip-172-31-74-118.ec2.internal
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=3.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.5-pre1
Path: eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
Newsgroups: comp.lang.ada
Subject: Re: Advent of Code Day 7
Date: Tue, 8 Dec 2020 12:25:54 +0100
Organization: Also freenews.netfront.net; news.tornevall.net;
 news.eternal-september.org
Message-ID: <rqnns2$b1v$1@dont-email.me>
References: <df3d282a-ff8c-4fd7-befc-a6ca683215e1n@googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Tue, 8 Dec 2020 11:25:54 -0000 (UTC)
Injection-Info: reader02.eternal-september.org; posting-host="3030b6eb4cf37069f3d0ce68eae32243";
	logging-data="11327"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX19/jaFFlqPJfedRXbyNRxYTn3wKKZZ0lk8="
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.5.0
Cancel-Lock: sha1:YT230mGz123Cgt0V6hO/jIyNnDM=
In-Reply-To: <df3d282a-ff8c-4fd7-befc-a6ca683215e1n@googlegroups.com>
Content-Language: en-US
Xref: reader02.eternal-september.org comp.lang.ada:60760
List-Id: <comp.lang.ada>

On 12/8/20 12:03 AM, John Perry wrote:
> 
>     type Bag_Entry is record
>        Description: Bag_Description := "                    ";

Humans are notoriously bad at counting things, and even worse at counting things 
they can't see, so this kind of literal can be a source of errors, especially 
during modification. (At least with Ada these tend to be compiler errors, not 
run-time errors.)

Of course, Ada offers a Better Way. You can write

    Description: Bag_Description := (Bag_Description'range => ' ');

or

    Description: Bag_Description := (others => ' ');

and be proof against any changes to Bag_Description's bounds.

I had a similar record, but I used Unbounded_String.

-- 
Jeff Carter
"Violence is the last refuge of the incompetent."
Foundation
151