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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Multiple iterators for a type
Date: Sat, 26 May 2018 08:59:55 +0200
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Xref: reader01.eternal-september.org comp.lang.ada:54835
Date: 2018-05-26T08:59:55+02:00
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On 2018-05-26 05:57, Luke A. Guest wrote:
> Stephen Leake <> wrote:
> 
>> An "iterator" can be anything you want it to be. As Randy pointed out,
>> there can be only one that gets special treatment from the compiler, but
>> you did not mention that as a requirement.
>>
> 
> I’m attempting to implement a Unicode string using UTF-8, so I want the
> basic iterator over octets, then the next will iterate over the octets and
> generate code points, then another will be graphème clusters.

Why do you bother? I mean, there is no solution for having a 
user-defined array type in Ada. Iterator is only a small part of it. 
Even if the iterator kludge worked somehow, the rest would not.

Multiple inheritance is not complete either, so having two array 
interfaces for one object will be extremely difficult and uncomfortable. 
You will end up with a mess of helper generic packages to emulate full 
inheritance. [I went that way, there is nothing good there.]

In short, there is nothing useful Ada 20xx could bring to the problem of 
dealing with encoded strings.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de