From: Florian Weimer <fw@deneb.enyo.de>
Subject: Re: Exclusive file access
Date: Sun, 30 Aug 2015 21:37:46 +0200
Date: 2015-08-30T21:37:46+02:00 [thread overview]
Message-ID: <87y4gsmut1.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: mvil865iebyb$.1of2shk5faacq$.dlg@40tude.net
* Dmitry A. Kazakov:
> On Sun, 30 Aug 2015 13:35:16 +0200, Florian Weimer wrote:
>
>> * Dmitry A. Kazakov:
>>
>>> No, I meant Wide_Wide_String.
>>>
>>> Ada's Wide_String is legally UCS-2. Windows is UTF-16. The only full
>>> Unicode string type is Wide_Wide_String. For an Indo-European language
>>> there is no difference, of course.
>>
>> GNAT's Wide_String should be compatible with UTF-16.
>
> In the sense that Wide_String is an array of 0..2**16-1 units of the
> endianness compatible to UTF-16, yes. However the standard is silent about
> endianness and alignment (a DSP processor might deploy 32-bit units per
> unit)
>
> Semantically no. Wide_String according to RM 3.5.2 (3/3) represents a
> narrower set of Unicode than UTF-16.
I don't have a current Windows system to try this, but I think Windows
allows you to use lone surrogates in file names. Such names are not
valid UTF-16, but valid UCS-2. If GNAT supports UCS-2 for
Wide_String, it would actually improve Windows compatibility.
>> Wide_Wide_String definitely is not.
>
> Definitely is. Both are to represent arrays of same sets of Unicode
> characters. The representation of Wide_Wide_String is of course irrelevant
> when used to specify an external file name, right?
You can end up with non-expressible names, depending on how the
conversion to the external representation is performed. (I.e., the
system may have file names which cannot be encoded as
Wide_Wide_String.)
next prev parent reply other threads:[~2015-08-30 19:37 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-27 13:52 Exclusive file access ahlan
2015-08-27 14:27 ` gautier_niouzes
2015-08-31 23:20 ` Randy Brukardt
2015-09-01 16:23 ` Pascal Obry
2015-09-01 20:48 ` Randy Brukardt
2015-08-27 14:42 ` Björn Lundin
2015-08-27 14:48 ` G.B.
2015-08-27 15:08 ` Björn Lundin
2015-08-27 18:38 ` tmoran
2015-08-27 23:16 ` Georg Bauhaus
2015-08-27 23:29 ` Pascal Obry
2015-08-28 7:25 ` Georg Bauhaus
2015-08-27 15:15 ` ahlan
2015-08-27 18:29 ` Jeffrey R. Carter
2015-08-28 5:41 ` ahlan
2015-08-28 7:10 ` Georg Bauhaus
2015-08-28 17:40 ` ahlan
2015-08-28 19:49 ` Anh Vo
2015-08-28 21:06 ` Simon Wright
2015-08-28 21:38 ` Jeffrey R. Carter
2015-08-29 7:05 ` Dmitry A. Kazakov
2015-08-29 8:31 ` Pascal Obry
2015-08-29 12:02 ` Dmitry A. Kazakov
2015-08-30 11:35 ` Florian Weimer
2015-08-30 12:44 ` Dmitry A. Kazakov
2015-08-30 19:37 ` Florian Weimer [this message]
2015-08-31 7:22 ` Dmitry A. Kazakov
2015-08-31 21:12 ` Florian Weimer
2015-09-01 7:26 ` Dmitry A. Kazakov
2015-09-07 18:27 ` Florian Weimer
2015-09-07 19:06 ` Dmitry A. Kazakov
2015-09-11 16:54 ` Florian Weimer
2015-08-31 23:34 ` Randy Brukardt
2015-09-01 7:33 ` Dmitry A. Kazakov
2015-08-29 16:07 ` gautier_niouzes
2015-08-29 17:12 ` Dmitry A. Kazakov
2015-09-01 12:37 ` brbarkstrom
2015-09-01 14:05 ` ahlan
2015-09-01 15:13 ` Simon Wright
2015-09-01 20:36 ` Randy Brukardt
2015-09-01 15:17 ` Jacob Sparre Andersen
2015-09-01 20:37 ` Randy Brukardt
2015-09-01 16:05 ` G.B.
2015-09-01 20:02 ` brbarkstrom
2015-09-01 21:17 ` Simon Wright
2015-09-05 15:52 ` Björn Lundin
2015-09-01 20:31 ` Randy Brukardt
2015-09-01 15:31 ` ahlan
2015-09-05 15:56 ` Björn Lundin
2015-09-06 17:38 ` brbarkstrom
2015-09-06 19:52 ` Björn Lundin
2015-09-07 15:18 ` brbarkstrom
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