pub fn unit<'a, I>() -> Parser<'a, I, ()>Expand description
Returns a Parser that does nothing.
何もしないParserを返します。
§Example
let text: &str = "a";
let input: Vec<char> = text.chars().collect::<Vec<_>>();
let parser: Parser<char, ()> = unit();
let result: ParseResult<char, ()> = parser.parse(&input);
assert!(result.is_success());
assert_eq!(result.success().unwrap(), ());