Function combine::parser::char::alpha_num

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

Parses either an alphabet letter or digit according to std::char::is_alphanumeric.

use combine::Parser;
use combine::parser::char::alpha_num;
assert_eq!(alpha_num().parse("A"), Ok(('A', "")));
assert_eq!(alpha_num().parse("1"), Ok(('1', "")));
assert!(alpha_num().parse("!").is_err());