nom-greedyerror

Custom error type of nom to take a deepest error.

The default error types of nom ( (I, ErrorKind) and VerboseError ) take a last challenged error at alt combinator. Alternatively GreedyError of nom-greedyerror take a deepest error.

Requirement

nom must be 5.0.0 or later.

Usage

[dependencies]
nom-greedyerror = "0.1.2"

Example

use super::*;
use nom::branch::alt;
use nom::character::complete::{alpha1, digit1};
use nom::error::{ParseError, VerboseError};
use nom::sequence::tuple;
use nom::IResult;
use nom_locate::LocatedSpan;

type Span<'a> = LocatedSpan<&'a str>;

fn parser<'a, E: ParseError<Span<'a>>>(
    input: Span<'a>,
) -> IResult<Span<'a>, (Span<'a>, Span<'a>, Span<'a>), E> {
    alt((
        tuple((alpha1, digit1, alpha1)),
        tuple((digit1, alpha1, digit1)),
    ))(input)
}

#[test]
fn test() {
    // VerboseError failed at
    //   abc012:::
    //   ^
    let error = parser::<VerboseError<Span>>(Span::new("abc012:::"));
    match error {
        Err(nom::Err::Error(e)) => {
            assert_eq!(e.errors.first().map(|x| x.0.position()), Some(0))
        }
        _ => (),
    };

    // GreedyError failed at
    //   abc012:::
    //         ^
    let error = parser::<GreedyError<Span>>(Span::new("abc012:::"));
    match error {
        Err(nom::Err::Error(e)) => assert_eq!(error_position(&e), Some(6)),
        _ => (),
    };
}

License

Licensed under either of

Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution