Function nom::multi::fold_many_m_n
source · [−]pub fn fold_many_m_n<I, O, E, F, G, H, R>(
min: usize,
max: usize,
parse: F,
init: H,
fold: G
) -> impl FnMut(I) -> IResult<I, R, E> where
I: Clone + InputLength,
F: Parser<I, O, E>,
G: FnMut(R, O) -> R,
H: FnMut() -> R,
E: ParseError<I>,
Expand description
Applies a parser n
times or until it fails and accumulates
the results using a given function and initial value.
Fails if the embedded parser does not succeed at least m
times.
Arguments
m
The minimum number of iterations.n
The maximum number of iterations.f
The parser to apply.init
A function returning the initial value.g
The function that combines a result off
with the current accumulator.
use nom::multi::fold_many_m_n;
use nom::bytes::complete::tag;
fn parser(s: &str) -> IResult<&str, Vec<&str>> {
fold_many_m_n(
0,
2,
tag("abc"),
Vec::new,
|mut acc: Vec<_>, item| {
acc.push(item);
acc
}
)(s)
}
assert_eq!(parser("abcabc"), Ok(("", vec!["abc", "abc"])));
assert_eq!(parser("abc123"), Ok(("123", vec!["abc"])));
assert_eq!(parser("123123"), Ok(("123123", vec![])));
assert_eq!(parser(""), Ok(("", vec![])));
assert_eq!(parser("abcabcabc"), Ok(("abc", vec!["abc", "abc"])));