The current version of UTF-16 is only capable of encoding 1,112,064 different numbers(code points); 0x0-0x10FFFF.
Does the Unicode Consortium Intend to make UTF-16 run out of characters?
i.e. make a code point > 0x10FFFF
If not, why would anyone write the code for a utf-8 parser to be able to accept 5 or 6 byte sequences? Since it would add unnecessary instructions to their function.
Isn't 1,112,064 enough, do we actually need MORE characters? I mean: How quickly are we running out?
As of 2011 we have consumed 109,449 characters AND set aside for application use(6,400+131,068):
leaving room for over 860,000 unused chars; plenty for CJK extension E(~10,000 chars) and 85 more sets just like it; so that in the event of contact with the Ferengi culture, we should be ready.
In November 2003 the IETF restricted UTF-8 to end at U+10FFFF with RFC 3629, in order to match the constraints of the UTF-16 character encoding: a UTF-8 parser should not accept 5 or 6 byte sequences that would overflow the utf-16 set, or characters in the 4 byte sequence that are greater than 0x10FFFF
Please put edits listing sets that pose threats on the size of the unicode code point limit here if they are over 1/3 the Size of the CJK extension E(~10,000 chars):
At present time, the Unicode standard doesn't define any characters above U+10FFFF, so you would be fine to code your app to reject characters above that point.
Predicting the future is hard, but I think you're safe for the near term with this strategy. Honestly, even if Unicode extends past U+10FFFF in the distant future, it almost certainly won't be for mission critical glyphs. Your app might not be compatible with the new Ferengi fonts that come out in 2063, but you can always fix it when it actually becomes an issue.
Cutting to the chase:
It is indeed intentional that the encoding system only supports code points up to U+10FFFF
It does not appear that there is any real risk of running out any time soon.
There is no reason to write a UTF-8 parser that supports 5-6 byte sequences, except for support of any legacy systems that actually used them. The current offical UTF-8 specification does not support 5-6 byte sequences in order to accomodate 100% loss-less conversions to/from UTF-16. If there is ever a time that Unicode has to support new codepoints above U+10FFFF, there will be plenty of time to devise new encoding formats for the higher bit counts. Or maybe by the time that happens, memory and computional power will be sufficient enough that everyone will just switch to UTF-32 for everything, which can handle up to U+FFFFFFFF for over 4 billion characters.
