Function combine::byte::oct_digit

pub fn oct_digit<I>() -> OctDigit<I> where
    I: Stream<Item = u8>, 

Parses an octal digit.

use combine::Parser;
use combine::byte::oct_digit;
assert_eq!(oct_digit().parse(&b"7"[..]), Ok((b'7', &b""[..])));
assert!(oct_digit().parse(&b"8"[..]).is_err());