Re: Thoughts on upsizing Unicode

Am 03.04.26 um 10:05 schrieb Rebecca Bettencourt via Unicode:
> My idea is to reallocate the Private Use High Surrogates to three- and 
> four-surrogate sequences using a UTF-8-like encoding, so that UTF-16 
> text without PUA characters remains unchanged. Only SPUA-A, SPUA-B, and 
> non-UTF16 characters would use new encoding forms.
[...]
> Of course, this is all just for speculation, as we are at least a couple 
> hundred years away from this actually being a problem.

This is all much too complicated. There is a much better solution, that 
wouldn't change any of the existing code points and would also allow for
relatively short encodings:

For UTF-8 simply use the now forbidden sequences starting with 0xFC or 
0xFD (maybe not 0xFE and 0xFF as this sometimes is missused for 
encoding-detection).
For ease of description let's say they introduce a 6-byte sequence, the 
first encodes only one bit (0xFC or 0xFD), the five follow-up bytes 6bit 
each, together using up the full 31bit range of UTF-32

For  UTF-16 simply use the now forbidden surrogate sequences as already
suggested (3 surrogates Hi-Hi-Lo or Hi-Lo-Lo each encoding 10 bits + one 
bit decided by using Hi or Lo in the middle for 31bits at all).

In both cases that's 6 byte to encode one codepoint above 0x10FFFF.

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Dominikus Dittes Scherkl