On Sat, Jan 25, 2020 at 8:00 PM Shiro Kawai <xxxxxx@gmail.com> wrote:

 It may include such surrogate as a character with the codepoint of unpaired surrogate,

I think it's a bad idea to even suggest that.  Isolated surrogates have no defined meaning and could only be treated as non-Unicode characters.  
or may raise a JSON error.

I believe it's right to raise an error just as if the JSON syntax was invalid, even though isolated surrogates are not actually invalid syntax.  In a forgiving mode they could be replaced by U+FFFD.

John Cowan          http://vrici.lojban.org/~cowan        xxxxxx@ccil.org
One time I called in to the central system and started working on a big
thick 'sed' and 'awk' heavy duty data bashing script.  One of the geologists
came by, looked over my shoulder and said 'Oh, that happens to me too.
Try hanging up and phoning in again.'  --Beverly Erlebacher