unicode-id

Determine if a char is a valid identifier for a parser and/or lexer according to Unicode Standard Annex #31 rules.

This is a clone of unicode-xid.

```rust use unicode_id::UnicodeID;

fn main() { let ch = 'a'; println!("Is {} a valid start of an identifier? {}", ch, UnicodeID::isidstart(ch)); } ```

features

unicode-id supports a no_std feature. This eliminates dependence on std, and instead uses equivalent functions from core.