Function winnow::multi::many_till0

source ·
pub fn many_till0<I, O, C, P, E, F, G>(
    f: F,
    g: G
) -> impl FnMut(I) -> IResult<I, (C, P), E>where
    I: Stream,
    C: Accumulate<O>,
    F: Parser<I, O, E>,
    G: Parser<I, P, E>,
    E: ParseError<I>,
Expand description

Applies the parser f until the parser g produces a result.

Returns a tuple of the results of f in a Vec and the result of g.

f keeps going so long as g produces ErrMode::Backtrack. To instead chain an error up, see cut_err.

To recognize a series of tokens, Accumulate into a () and then Parser::recognize.

Example

use winnow::multi::many_till0;
use winnow::bytes::tag;

fn parser(s: &str) -> IResult<&str, (Vec<&str>, &str)> {
  many_till0(tag("abc"), tag("end"))(s)
};

assert_eq!(parser("abcabcend"), Ok(("", (vec!["abc", "abc"], "end"))));
assert_eq!(parser("abc123end"), Err(ErrMode::Backtrack(Error::new("123end", ErrorKind::Tag))));
assert_eq!(parser("123123end"), Err(ErrMode::Backtrack(Error::new("123123end", ErrorKind::Tag))));
assert_eq!(parser(""), Err(ErrMode::Backtrack(Error::new("", ErrorKind::Tag))));
assert_eq!(parser("abcendefg"), Ok(("efg", (vec!["abc"], "end"))));