winnow::combinator

Function separated_foldl1

Source
pub fn separated_foldl1<Input, Output, Sep, Error, ParseNext, SepParser, Op>(
    parser: ParseNext,
    sep: SepParser,
    op: Op,
) -> impl Parser<Input, Output, Error>
where Input: Stream, ParseNext: Parser<Input, Output, Error>, SepParser: Parser<Input, Sep, Error>, Error: ParserError<Input>, Op: FnMut(Output, Sep, Output) -> Output,
Expand description

Alternates between two parsers, merging the results (left associative)

This stops when either parser returns ErrMode::Backtrack. To instead chain an error up, see cut_err.

ยงExample

use winnow::combinator::separated_foldl1;
use winnow::ascii::dec_int;

fn parser(s: &str) -> IResult<&str, i32> {
  separated_foldl1(dec_int, "-", |l, _, r| l - r).parse_peek(s)
}

assert_eq!(parser("9-3-5"), Ok(("", 1)));
assert_eq!(parser(""), Err(ErrMode::Backtrack(InputError::new("", ErrorKind::Token))));
assert_eq!(parser("def|abc"), Err(ErrMode::Backtrack(InputError::new("def|abc", ErrorKind::Verify))));