Re: System.WCh_Cnv

["Björn Persson" <spam-away@nowhere.nil>]

demoonlit@panathenaia.halfmoon.jp wrote:
> Windows comand prompt

OK, so your OS is Windows.

> So I'd convert JIS character code to other code set(with iconv,
> mbstowcs, etc).

Do you have Iconv? I thought that wasn't available in Windows.

> And other Ada packages assume Wide_String as Unicode. I think it's
> natural, because C-functions assume wchar_t as Unicode.
> If at all possible, I want take Wide_String as Unicode same as
> C-runtime functions.

Let's get some things straight so that we'll understand each other 
better. Unicode defines several character encodings. When you write 
"Unicode", do you mean UTF-8, UTF-16, UCS-4 (also called UTF-32) or 
UCS-2? Ada's Wide_String is UCS-2 and Wide_Wide_String is UCS-4. In C 
it's implementation-defined how wide a wide character is. As far as I 
know, wchar_t is usually 32 bits in Unix, so that a "wide string" is 
UCS-4. I hear Microsoft uses 16 bits for wchar_t, but I'm not sure 
whether a "wide string" in Windows is treated as UCS-2 or UTF-16.

> System.WCh_Cnv confound JIS character code with Unicode, it makes
> troubles. Wide_Text_IO (and -gnatWs, -gantWe) are useless in fact,
> because there is no what uses JIS character code as it is, conversion
> is needed after all.

I haven't used that package myself so I don't know how it works, but I 
won't be surprised if it's buggy. In my experience, Adacore's handling 
of character encodings is rather unimpressive.

> So, I want to know why System.WCh_Cnv takes JIS character code?

As it's a Gnat-specific package, only Adacore knows why they did it the 
way they did. You could ask them, but I don't think they'll answer this 
kind of questions unless you buy a support contract.

-- 
Bj�rn Persson                              PGP key A88682FD
                    omb jor ers @sv ge.
                    r o.b n.p son eri nu