Function winnow::sequence::preceded

source ·
pub fn preceded<I, O1, O2, E: ParseError<I>, F, G>(
    first: F,
    second: G
) -> impl FnMut(I) -> IResult<I, O2, E>where
    I: Stream,
    F: Parser<I, O1, E>,
    G: Parser<I, O2, E>,
Expand description

Apply two parsers, only returning the output from the second.

Arguments

  • first The opening parser.
  • second The second parser to get object.

Example

use winnow::sequence::preceded;
use winnow::bytes::tag;

let mut parser = preceded(tag("abc"), tag("efg"));

assert_eq!(parser("abcefg"), Ok(("", "efg")));
assert_eq!(parser("abcefghij"), Ok(("hij", "efg")));
assert_eq!(parser(""), Err(ErrMode::Backtrack(Error::new("", ErrorKind::Tag))));
assert_eq!(parser("123"), Err(ErrMode::Backtrack(Error::new("123", ErrorKind::Tag))));