* Re: Ada and Unicode
@ 2022-04-03 18:04 4% ` Thomas
0 siblings, 0 replies; 3+ results
From: Thomas @ 2022-04-03 18:04 UTC (permalink / raw)
In article <s5k0ai$bb5$1@dont-email.me>, "J-P. Rosen" <rosen@adalog.fr>
wrote:
> Le 19/04/2021 à 15:00, Luke A. Guest a écrit :
> > They're different types and should be incompatible, because, well, they
> > are. What does Ada have that allows for this that other languages
> > doesn't? Oh yeah! Types!
>
> They are not so different. For example, you may read the first line of a
> file in a string, then discover that it starts with a BOM, and thus
> decide it is UTF-8.
could you give me an example of sth that you can do yet, and you could
not do if UTF_8_String was private, please?
(to discover that it starts with a BOM, you must look at it.)
>
> BTW, the very first version of this AI had different types, but the ARG
> felt that it would just complicate the interface for the sake of abusive
> "purity".
could you explain "abusive purity" please?
i guess it is because of ASCII.
i guess a lot of developpers use only ASCII in a lot of situation, and
they would find annoying to need Ada.Strings.UTF_Encoding.Strings every
time.
but I think a simple explicit conversion is acceptable, for a not fully
compatible type which requires some attention.
the best would be to be required to use ASCII_String as intermediate,
but i don't know how it could be designed at language level:
UTF_8_Var := UTF_8_String (ASCII_String (Latin_1_Var));
Latin_1_Var:= String (ASCII_String (UTF_8_Var));
and this would be forbidden :
UTF_8_Var := UTF_8_String (Latin_1_Var);
this would ensures to raise Constraint_Error when there are somme
non-ASCII characters.
--
RAPID maintainer
http://savannah.nongnu.org/projects/rapid/
^ permalink raw reply [relevance 4%]
* Re: I need to show extended Ascii codes in GtkAda environment
2019-11-22 21:22 7% ` Randy Brukardt
@ 2019-11-22 21:36 5% ` Dmitry A. Kazakov
0 siblings, 0 replies; 3+ results
From: Dmitry A. Kazakov @ 2019-11-22 21:36 UTC (permalink / raw)
On 2019-11-22 22:22, Randy Brukardt wrote:
> Slash_Null : constant String :=
> Ada.Strings.UTF_Encoding.Strings.Encode (Character'Val(216) & "");
Or using array aggregate
Ada.Strings.UTF_Encoding.Strings.Encode ((1=>Character'Val(216)));
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
^ permalink raw reply [relevance 5%]
* Re: I need to show extended Ascii codes in GtkAda environment
@ 2019-11-22 21:22 7% ` Randy Brukardt
2019-11-22 21:36 5% ` Dmitry A. Kazakov
0 siblings, 1 reply; 3+ results
From: Randy Brukardt @ 2019-11-22 21:22 UTC (permalink / raw)
"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
news:qr8qbp$15gp$1@gioia.aioe.org...
> On 2019-11-22 14:09, L Dries wrote:
>> In a GtkAda environment I have the need to present some characters or
>> strings with characters in the Extended character Ascii range for
>> instance O with slash (216). I create a constant character with
>>
>> Slash_null : constant string(1 .. 1) := "" & character'Val(216);
>
> GTK is UTF-8. You must encode and decode anything that is not ASCII 7-bit.
> [A pragmatic approach is to ignore the reference manual and treat all
> strings UTF-8 rather than mandated Latin 1.]
>
> Anyway, assuming you need the LATIN CAPITAL LETTER O WITH STROKE character
> (code point 216), encoded in UTF-8 it is C3 98. Note, two octets. Thus:
>
> Slash_Null : constant String :=
> Character'Val (16#C3#) & Character'Val (16#98#);
>
> With Strings Edit for Ada you could also write:
>
> Slash_Null : constant String := Strings_Edit.UTF8.Image (216);
You could of course use Ada.Strings.UTF_Encoding (a standard part of Ada
2012) to do this as well, by converting the "standard" Latin-1 String to
UTF-8:
with Ada.Strings.UTF_Encoding.Strings;
...
Slash_Null : constant String :=
Ada.Strings.UTF_Encoding.Strings.Encode (Character'Val(216) & "");
Note that concatenating the character with the null string effectively
creates a string with one character. (You could of course use the literal
directly if your editor/implementation supports that - tough to do that on
the Internet, though.)
Randy.
^ permalink raw reply [relevance 7%]
Results 1-3 of 3 | reverse | options above
-- pct% links below jump to the message on this page, permalinks otherwise --
2019-11-22 13:09 I need to show extended Ascii codes in GtkAda environment L Dries
2019-11-22 14:12 ` Dmitry A. Kazakov
2019-11-22 21:22 7% ` Randy Brukardt
2019-11-22 21:36 5% ` Dmitry A. Kazakov
2021-04-17 22:03 Ada and Unicode DrPi
2021-04-19 9:08 ` Stephen Leake
2021-04-19 11:56 ` Luke A. Guest
2021-04-19 12:52 ` Dmitry A. Kazakov
2021-04-19 13:00 ` Luke A. Guest
2021-04-19 13:24 ` J-P. Rosen
2022-04-03 18:04 4% ` Thomas
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