> So if a PI has a target and data, what is the data in the following scenarios?
>
> <?Foo?>
> <?Foo ?>
>
> Is the first null data and the second a string of spaces?
The first case is definitely null data. Production 16 says that
the optional data is prefixed by one or more whitespace characters
which are not part of it. So the second case has data consisting of
a zero-length string. It wouldn't astonish me if some parsers
returned null in both cases.
However, trailing whitespace is left alone.
-- John Cowan cowan@ccil.org e'osai ko sarji la lojban.