Surrogates and noncharacters

Doug Ewell doug at
Mon May 11 12:44:19 CDT 2015

Hans Aberg <haberg dash 1 at telia dot com> wrote:

>>> However I wonder what would be the effect of D80 in UTF-32: is
>>> <0xFFFFFFFF> a valid "32-bit string" ?
>> The value 0xFFFFFFFF cannot appear in a UTF-32 string. Therefore it
>> cannot represent a unit of encoded text in a UTF-32 string.
> Even though the values with highest bit set are not a part of original
> UTF-32, it can easily be extended also to original UTF-8, which may be
> simpler to implement.

"Original UTF-8," regardless of where defined, only ever encoded scalar
values up to 0x7FFFFFFF. See, for example, RFC 2279.

Doug Ewell | | Thornton, CO ����

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