Function nom::sequence::preceded

pub fn preceded<I, O1, O2, E: ParseError<I>, F, G>(
    first: F, 
    second: G
) -> impl Fn(I) -> IResult<I, O2, E> where
    F: Fn(I) -> IResult<I, O1, E>,
    G: Fn(I) -> IResult<I, O2, E>, 

Matches an object from the first parser and discards it, then gets an object from the second parser.

Arguments

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

use nom::sequence::preceded;
use nom::bytes::complete::tag;

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

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