Re: Unibyte characters, strings, and buffers

[David Kastrup]

Andreas Schwab <address@hidden> writes:

> David Kastrup <address@hidden> writes:
>
>> "Stephen J. Turnbull" <address@hidden> writes:
>>
>>> I agree that having a way to represent "undecodable bytes" in a string
>>> or buffer is extremely convenient.  XEmacs's lack of this capability
>>> is surely a deficiency (Hi, David K!)
>>
>> Doing this in an utf-8 based internal coding is somewhat doable by
>> employing non-utf-8 sequences.  Either using code points above the
>> Unicode code range (2^20 + something, requiring 4 bytes), or by using
>> non-minimal encodings (since the minimal ones are two bytes, requiring 3
>> bytes).  Either way, the size increases significantly.
>
> Emacs uses U3fff80-U3fffff for raw 8-bit bytes, internally represented
> by 2 bytes.

Well, I forgot the non-minimal encodings for 0x00-0x7f, namely two-byte
sequences starting with 0xc0 or 0xc1 and ending with 0x80-0xbf.

Those would still fit the representation invariants.  Are those the
two-byte encodings used for "raw 0x80 to 0xff"?

-- 
David Kastrup