Re: I need to show extended Ascii codes in GtkAda environment

["Randy Brukardt" <randy@rrsoftware.com>]

"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.