Determine if a char
is a valid identifier for a parser and/or lexer according to
Unicode Standard Annex #31 rules.
extern crate unicode_xid;
use unicode_xid::UnicodeXID;
fn main() {
let ch = 'a';
println!("Is {} a valid start of an identifier? {}", ch, UnicodeXID::is_xid_start(ch));
}
unicode-xid supports a no_std
feature. This eliminates dependence
on std, and instead uses equivalent functions from core.