Re: XC8 novice question

From	Hans-Bernhard Bröker <HBBroeker@t-online.de>
Newsgroups	comp.arch.embedded
Subject	Re: XC8 novice question
Date	2016-09-12 22:52 +0200
Message-ID	<e3oiskFtrj5U1@mid.dfncis.de> (permalink)
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Am 11.09.2016 um 15:14 schrieb upsidedown@downunder.com:
> On Sun, 11 Sep 2016 13:36:59 +0200, Hans-Bernhard Bröker
> <HBBroeker@t-online.de> wrote:

>> It may appear to provide a solution to the issue: "How to keep non-ASCII
>> characters in a plain char?"

> Unsigned char was the answer for at least 5-10 years before UCS2.

It really wasn't, because as a solution it was incoherent, incomplete, 
and insular.  Anyway, there really weren't that many years between C90 
and UCS2.

8-bit unsigned char for non-ASCII characters created more problems than 
it ever solved.  Instead of having one obvious, while painful 
restriction, we now had

*) dozens of conflicting interpretations of the same 256 values,
*) no standard way of knowing which of those applied to given input
*) almost no way of combining multiple such streams internally
*) no useful way of outputting a combined stream

> For correctly storing Unicode characters, a 21 bit data type is
> required.

Not quite.  You need a type with _at_least_ 21 bits.  It doesn't have to 
be a 21-bit data type.

> Having done IT applications for more than 30 years, the problem was
> well known in those days.

The problem: yes.  But essentially nobody dared to implement an actual 
solution.

C itself has had some support for wider character representations and 
all that from the get-go (i.e. the first actual standard in 1990), but I 
don't think I've ever seen anyone use that in anger.

> The video (dot matrix) display units of those days were not capable of
> displaying very good glyphs, but still good for Latin, Cyrillic or
> Arabic glyphs, but ware quite bad on Est-Asian glyphs.

But they could generally only display Latin, Cyrillic, _or_ Arabic, but 
not all of them on the same screen.  I.e. they suffered from the same 
problem as using 8-bit unsigned for 'char' does: one more bit just isn't 
enough to do the job.

Thread

XC8 novice question rwood <rwoodl@nowhere.com> - 2016-09-11 15:02 +0800
  Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-11 02:55 -0700
    Re: XC8 novice question rwood <rwoodl@nowhere.com> - 2016-09-11 18:25 +0800
      Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-11 13:35 +0200
        Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-11 07:32 -0700
          Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-11 16:58 +0200
            Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-11 13:15 -0700
              Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-12 08:55 +0200
                Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-12 02:41 -0700
                Re: XC8 novice question Mike Perkins <spam@spam.com> - 2016-09-12 13:16 +0100
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-12 14:56 +0200
                Re: XC8 novice question Mike Perkins <spam@spam.com> - 2016-09-12 14:33 +0100
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-12 16:11 +0200
                Re: XC8 novice question Jack <jack4747@gmail.com> - 2016-09-12 07:50 -0700
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-12 22:23 +0200
                Re: XC8 novice question Les Cargill <lcargill99@comcast.com> - 2016-09-12 15:34 -0500
                Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-12 08:44 -0700
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-12 14:35 +0200
                Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-12 08:19 -0700
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-12 23:11 +0200
                Re: XC8 novice question Dennis <dennis@none.none> - 2016-09-12 17:04 -0500
                Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-12 22:49 -0700
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-13 09:04 +0200
                Re: XC8 novice question Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2016-09-13 00:16 +0200
                Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-12 21:22 -0700
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-13 12:25 +0200
                Re: XC8 novice question Dennis <dennis@none.none> - 2016-09-13 10:22 -0500
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-13 20:08 +0200
            Re: XC8 novice question rwood <rwoodl@nowhere.com> - 2016-09-12 16:50 +0800
          Re: XC8 novice question Tom Gardner <spamjunk@blueyonder.co.uk> - 2016-09-11 17:13 +0100
            Re: XC8 novice question Tom Gardner <spamjunk@blueyonder.co.uk> - 2016-09-11 17:19 +0100
              Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-12 09:00 +0200
      Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-11 07:28 -0700
    Re: XC8 novice question upsidedown@downunder.com - 2016-09-11 13:56 +0300
      Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-11 13:28 +0200
      Re: XC8 novice question Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2016-09-11 13:36 +0200
        Re: XC8 novice question upsidedown@downunder.com - 2016-09-11 16:14 +0300
          Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-11 07:57 -0700
          Re: XC8 novice question Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2016-09-12 22:52 +0200
            Re: XC8 novice question upsidedown@downunder.com - 2016-09-13 10:11 +0300
              Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-13 01:11 -0700
                Re: XC8 novice question upsidedown@downunder.com - 2016-09-13 13:24 +0300
                Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-13 12:39 +0200
                Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-13 15:41 -0700
                Re: XC8 novice question upsidedown@downunder.com - 2016-09-14 09:07 +0300
                Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-13 23:29 -0700
      Re: XC8 novice question Don Y <blockedofcourse@foo.invalid> - 2016-09-11 07:50 -0700
  Re: XC8 novice question Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2016-09-11 13:42 +0200
  Re: XC8 novice question Tim Wescott <tim@seemywebsite.com> - 2016-09-11 20:14 -0500
  Re: XC8 novice question rwood <rwoodl@nowhere.com> - 2016-09-12 16:54 +0800
    Re: XC8 novice question David Brown <david.brown@hesbynett.no> - 2016-09-12 11:05 +0200
      Re: XC8 novice question rwood <rwoodl@nowhere.com> - 2016-09-12 18:48 +0800
  Re: XC8 novice question John Temples <usenet@xargs-spam.com> - 2016-09-12 17:33 +0000

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