Re: unicode and wide_text_io

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On 2017-12-28 14:15, Mehdi Saada wrote:

> Ok, I'm done with it. It sure is interesting, but I don't want to
> even think about all this stuff for the time being... Talk about
> "universal  standard", when it's (apparently) it's far from universal or uniform !

It is. Everybody uses UTF-8. Even under Windows. The text is converted 
from/to UTF-16 right after or before passing it to the system call. All 
processing is UTF-8. E.g. GTK uses UTF-8 consistently no matter what OS.

>> Easy: it uses a variable-width representation.
> Under the assumption terminals will be able to display it... well,
> whatever I use in the end, I've got to suppose it anyway.

Sure they are Linux and Windows.

Take this program:
------------------------------------
with Ada.Text_IO;  use Ada.Text_IO;
procedure Superscript is
begin
    Put_Line
    (  "Superscript 1="
    &  Character'Val (194)
    &  Character'Val (185)
    );
end Superscript;
------------------------------------
Start Windows console:

 > gnatmake superscript.adb
 > chcp 65001
 > superscript

This will, depending on the font, nicely output:

Superscript 1=¹

P.S. Batch command chcp selects the code page of the console. 65001 is 
for UTF-8.

P.P.S. Some Windows fonts do not have sub-/superscript glyphs. So you 
might wish to set the console to Lucida or some other fixed space font 
with Unicode support.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de