Re: Ada.Bounded_Strings

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Fri, 4 Apr 2008 23:55:56 -0500, Randy Brukardt wrote:

> "Adam Beneschan" <adam@irvine.com> wrote in message
> news:444c0bf9-a2ad-4280-8d69-58d59938f69e@d2g2000pra.googlegroups.com...
> ...
>> Again, this doesn't sound reasonable in the context of the sort of
>> "business applications" that I used to work on in COBOL.  For other
>> types of applications, it's probably OK, or Ada.Strings.Unbounded may
>> be best.  The reason I'm even thinking about all this is that I had
>> been hoping for a number of years now that Ada would be able to make
>> inroads into "business" applications and maybe be seen as an
>> alternative to COBOL, and I'm a bit disappointed that, AFAIK, nothing
>> or very little has happened in that arena.  Not that I think
>> Ada.Strings.Bounded is a major reason for this, or that providing a
>> better string-handling facility would help at all.  (shrug)
> 
> I think that the inability to write a package that "naturally" uses literals
> (and possibly indexing and slicing) for a private type are also large
> impediments.

+ classes of all types. All string types shall become members of one class.

> (Worse, the current string packages cannot be retrofitted to
> use such a capability even if it was added to Ada, lessening the possibility
> of doing that.)

Why is this a problem? Old packages could be re-implemented using new
features with the specifications left as-is for backward compatibility.

> Net-net, I think the string packages are a disaster: just good enough to
> prevent them from being properly replaced, but not good enough to use in a
> natural way. (And Ada doesn't do anything useful to support UTF-8, which
> doesn't help matters any.)

I see encodings as a different and more difficult problem. All strings are
implementations of an abstract array interface. With different encoding not
only the arrays, but also their elements will have a class: ASCII, Latin-1,
UCS-2, full Unicode. I have no idea how to handle that keeping all strings
in one class. Further, there is the presentation layer (when, say, UTF-8 is
seen as a sequence of octets). I am not sure if that need to be exposed.
Probably it has to be in order to interface other languages.

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