Function try_parse_from_str 

pub fn try_parse_from_str<'a, F, E>(
    s: &mut &'a str,
    parse: F,
) -> Result<Result<&'a str, E>, E>
where
    F: FnOnce(&mut &'a str) -> Result<(), E>,
    E: ParseError,

[Parser::try_parse] for strings