Restrict to the BMP
Restrict to the BMP

ANTLR only supports code points up to U+FFFF, and I agree with the Unicode Consortium that UTF-32 is a waste of storage.

As such, this implementation will use UTF-16 source files. This means that we will need to handle surrogate pairs for the lexer/parser.

nafi-lang/J-NAFI,nafi-lang/J-NAFI