Tom Lane wrote:
> Sam Mason <sam@samason.me.uk> writes:
>
>> I'd never heard of UTF-16 surrogate pairs before this discussion and
>> hence didn't realise that it's valid to have a surrogate pair in place
>> of a single code point. The docs say that <D800 DF02> corresponds to
>> U+10302, Python would appear to follow my intuitions in that:
>>
>
>
>> ord(u'\uD800\uDF02')
>>
>
>
>> results in an error instead of giving back 66306, as I'd expect. Is
>> this a bug in Python, my understanding, or something else?
>>
>
> I might be wrong, but I think surrogate pairs are expressly forbidden in
> all representations other than UTF16/UCS2. We definitely forbid them
> when validating UTF-8 strings --- that's per an RFC recommendation.
> It sounds like Python is doing the same.
>
>
>
You mustn't encode the surrogate, but it's up to us how we allow people
to designate a given code point.
Frankly, I think we shouldn't provide for using surrogates at all. I
would prefer something like \uXXXX for BMP items and \UXXXXXXXX as the
straight 32bit designation of a higher codepoint.
cheers
andrew