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!aioe.org!JUN8/iIzeA71QWaIWFKODA.user.gioia.aioe.org.POSTED!not-for-mail From: "Luke A. Guest" Newsgroups: comp.lang.ada Subject: Re: Ada and Unicode Date: Mon, 19 Apr 2021 14:15:24 +0100 Organization: Aioe.org NNTP Server Message-ID: References: <607b5b20$0$27442$426a74cc@news.free.fr> <86mttuk5f0.fsf@stephe-leake.org> NNTP-Posting-Host: JUN8/iIzeA71QWaIWFKODA.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 Content-Language: en-GB X-Notice: Filtered by postfilter v. 0.9.2 Xref: reader02.eternal-september.org comp.lang.ada:61843 List-Id: On 19/04/2021 14:10, Dmitry A. Kazakov wrote: >> They're different types and should be incompatible, because, well, > they are. What does Ada have that allows for this that other languages > doesn't? Oh yeah! Types! > > They are subtypes, differently constrained, like Positive and Integer. No they're not. They're subtypes only and therefore compatible. The UTF string isn't constrained in any other ways. > Operations are same values are differently constrained. It does not make > sense to consider ASCII 'a', Latin-1 'a', UTF-8 'a' different. It is > same glyph differently encoded. Encoding is a representation aspect, > ergo out of the interface! As I already said in Unicode the glyph is not part part of Unicode. The single code point character concept doesn't exist anymore. > > BTW, subtype is a type. > subtype is a compatible type.