Re: new console server code checked in

[Yoshinori K. Okuji]

At Wed,  5 Jun 2002 05:38:38 -0400 (EDT),
Roland McGrath wrote:
> I was (and am still sort of) unclear on UTF-32 vs UCS-4.

Their formats are identical but their semantics is different, because
UCS-4 is defined in ISO/IEC 10646, while UTF-32 is defined in Unicode
Standard.

Basically ISO/IEC 10646 is a standard only for characters (in normal
sense), so you may not represent invalid characters in UCS-4
(e.g. 0xFFFF).

On the other hand, UTF-32 disallows you to use any code value that
cannot be coded in UTF-16, that is, you can use only the range
[0x00000000, 0x0010FFFF].

There are some other differences, but, in brief, you can assume that
they are the same, as long as you use them as internal encodings.

Cheers,
Okuji