Function combine::parser::char::hex_digit

pub fn hex_digit<Input>(
) -> impl Parser<Input, Output = char, PartialState = ()> where
    Input: Stream<Token = char>,
    Input::Error: ParseError<Input::Token, Input::Range, Input::Position>, 

Parses a hexdecimal digit with uppercase and lowercase.

use combine::Parser;
use combine::parser::char::hex_digit;
assert_eq!(hex_digit().parse("F"), Ok(('F', "")));
assert!(hex_digit().parse("H").is_err());