On 4/16/09, Tom Lane <tgl@sss.pgh.pa.us> 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.
The point here is that Python/Java/C# allow them for escaping non-BMP
unicode values, irrespective of their interal encoding.
--
marko