From: Martin Krischik <krischik@users.sourceforge.net>
Subject: Re: UTF-8 in strings - a bug?
Date: Sat, 08 May 2004 18:25:19 +0200
Date: 2004-05-08T18:25:19+02:00 [thread overview]
Message-ID: <3171026.RJblE7u9LK@linux1.krischik.com> (raw)
In-Reply-To: 4b3nc.58514$mU6.237399@newsb.telia.net
Bjï¿œrn Persson wrote:
> -- Latin1 string (contains bytes associated with code points in
> Latin1)
> -- | "use Unicode.CES.Basic_8bit.To_Utf32"
> -- v
Basic_8bit.To_Utf32 only make an 8bit -> 32bit expansion that is 16#xx#
becomes 16#000000xx#. The result is not really unicode but needed for
further convertions.
> -- Utf32 latin1 string (contains code points in Latin1)
> -- | "Convert argument to To_Utf32 should be
> -- v Unicode.CCS.Iso_8859_1.Convert"
This does the actual convertion. The result is now unicode.
> -- Utf32 Unicode string (contains code points in Unicode)
> -- | "use Unicode.CES.Utf8.From_Utf32"
> -- v
Now we have standart UTF-8.
> -- Utf8 Unicode string (contains code points in Unicode)
> -- | "Convert argument to From_Utf32 should be
> -- v Unicode.CCS.Iso_8859_2.Convert"
Now this is some Latin-2 optimized UTF-8. If this is truly usefull I don't
know.
> -- Utf8 Latin2 string (contains code points in Latin2)
>
>
> Investigating furter, I see that docs/xml_2.html shows the exact same
> example of converting Latin-1 to "Utf8 Latin2".
The UTF-X encodings can start with a BOM "Byte-order mark". This changes the
behaviour of the encoding:
------------------------------
-- Byte-order mark handling --
------------------------------
type Bom_Type is
(Utf8_All, -- Utf8-encoding
Utf16_LE, -- Utf16 little-endian encoding
Utf16_BE, -- Utf16 big-endian encoding
Utf32_LE, -- Utf32 little-endian encoding
Utf32_BE, -- Utf32 big-endian encoding
Ucs4_BE, -- UCS-4, big endian machine (1234 order)
Ucs4_LE, -- UCS-4, little endian machine (4321 order)
Ucs4_2143, -- UCS-4, unusual byte order (2143 order)
Ucs4_3412, -- UCS-4, unusual byte order (3412 order)
Unknown); -- Unknown, assumed to be ASCII compatible
BTW: I am currently adding Wide_Character support to the XMLAda/Unicode
package.
With Regards
Martin
--
mailto://krischik@users.sourceforge.net
http://www.ada.krischik.com
next prev parent reply other threads:[~2004-05-08 16:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-05-05 22:12 UTF-8 in strings - a bug? Björn Persson
2004-05-05 23:31 ` Robert I. Eachus
2004-05-06 8:34 ` Björn Persson
2004-05-06 9:25 ` Ludovic Brenta
2004-05-06 17:13 ` Björn Persson
2004-05-06 18:24 ` Martin Krischik
2004-05-07 23:32 ` Björn Persson
2004-05-08 6:38 ` Martin Krischik
2004-05-08 7:44 ` Jacob Sparre Andersen
2004-05-08 11:06 ` Björn Persson
2004-05-08 16:25 ` Martin Krischik [this message]
2004-05-09 12:16 ` Georg Bauhaus
2004-05-10 6:29 ` Martin Krischik
2004-05-08 12:10 ` Georg Bauhaus
2004-05-06 9:06 ` David Starner
2004-05-06 17:36 ` Björn Persson
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