Function nom::multi::fold_many1
source · pub fn fold_many1<I, O, E, F, G, H, R>(
f: F,
init: H,
g: 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
Repeats the embedded parser, calling g
to gather the results.
This stops on Err::Error
if there is at least one result. To instead chain an error up,
see cut
.
§Arguments
f
The parser to apply.init
A function returning the initial value.g
The function that combines a result off
with the current accumulator.
Note: If the parser passed to many1
accepts empty inputs
(like alpha0
or digit0
), many1
will return an error,
to prevent going into an infinite loop.
use nom::multi::fold_many1;
use nom::bytes::complete::tag;
fn parser(s: &str) -> IResult<&str, Vec<&str>> {
fold_many1(
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"), Err(Err::Error(Error::new("123123", ErrorKind::Many1))));
assert_eq!(parser(""), Err(Err::Error(Error::new("", ErrorKind::Many1))));