In 9.1.3 we see
Text must consist of valid Unicode characters other than U+0000. Text
should not contain control characters other than space characters.
Later in 9.2.3.1 we find:
If the number is not a valid Unicode character (e.g. if the number is
higher than 1114111), or if the number is zero, then return a character
token for the U+FFFD REPLACEMENT CHARACTER character instead.
I do not think the Unicode spec defines the notion of a "valid Unicode
character". (It does define a valid Unicode code unit sequence, but
that's a little different. A code unit sequence generally consists of
more than one character.) Thus I suggest we need to be more precise here
about what is and is not a valid Unicode character. In particular:
1. Are private use characters allowed?
2. Are control characters allowed (probably yes, based on other parts of
the spec).
3. Are surrogate characters allowed? (probably no)
4. Are non-characters beyond 10FFFF allowed (no)
5. Are reserved but currently undefined characters allowed (yes)
6. Are noncharacters U+FDD0..U+FDEF allowed (?)
7. Are the noncharacters from the last two characters of each plane
allowed (?)
--
Elliotte Rusty Harold [EMAIL PROTECTED]
Java I/O 2nd Edition Just Published!
http://www.cafeaulait.org/books/javaio2/
http://www.amazon.com/exec/obidos/ISBN=0596527500/ref=nosim/cafeaulaitA/
