epage
commented
8 months ago I've added parse_nexts to help demonstrate what is happening
#!/usr/bin/env nargo
---
[dependencies]
winnow.path = "../winnow"
---
use winnow::ascii::{alpha1, digit1, multispace0};
use winnow::combinator::{delimited, opt, repeat};
use winnow::{PResult, Parser};
fn main() {
let input1 = r#"(123,456,789)
(000,111,22~~~2)
"#;
let offset1 = parse_digits.parse(input1).err().unwrap().offset();
dbg!(offset1); // offset position error
let mut input1 = r#"(123,456,789)
(000,111,22~~~2)
"#;
parse_digits.parse_next(&mut input1);
dbg!(input1);
let input2 = r#"(123,456,789)
(000,1~~~11,222)
"#;
let offset2 = parse_digits.parse(input2).err().unwrap().offset();
dbg!(offset2); // offset position error
let mut input2 = r#"(123,456,789)
(000,1~~~11,222)
"#;
parse_digits.parse_next(&mut input2);
dbg!(input2);
assert_eq!(offset1, offset2);
}
fn parse_digits<'a>(input: &mut &'a str) -> PResult<Vec<Vec<&'a str>>> {
delimited(multispace0, repeat(1.., digit_group), multispace0).parse_next(input)
}
fn digit_group<'a>(input: &mut &'a str) -> PResult<Vec<&'a str>> {
delimited(
(multispace0, '(', multispace0),
repeat(1.., (digit1, opt(",")).map(|x| x.0)),
(multispace0, ')', multispace0),
)
.parse_next(input)
}$ ./winnow-426.rs
[/home/epage/.cargo/target/05/6398075af02aec/winnow-426.rs:16] offset1 = 18
[/home/epage/.cargo/target/05/6398075af02aec/winnow-426.rs:22] input1 = "(000,111,22~~~2)\n "
[/home/epage/.cargo/target/05/6398075af02aec/winnow-426.rs:28] offset2 = 18
[/home/epage/.cargo/target/05/6398075af02aec/winnow-426.rs:34] input2 = "(000,1~~~11,222)\n "When encountering the second group, digit_group fails. The repeat inside of parse_digits then backtracks, finds the repeat is satisfied, and then finds parse_digits is satisfied. parse_next then succeeds, pointing at the start of the second group. The error then comes from the implicit eof that is a part of parse.
You can verify this by running with the debug feature
$ nargo run --manifest-path winnow-426.rs -F winnow/debug
> delimited | "(123,456,789)\n (000,111,22~~~2)\n
> multispace0 | "(123,456,789)\n (000,111,22~~~2)\n
> take_while | "(123,456,789)\n (000,111,22~~~2)\n
< take_while | +0
< multispace0 | +0
> repeat | "(123,456,789)\n (000,111,22~~~2)\n
> delimited | "(123,456,789)\n (000,111,22~~~2)\n
> multispace0 | "(123,456,789)\n (000,111,22~~~2)\n
> take_while | "(123,456,789)\n (000,111,22~~~2)\n
< take_while | +0
< multispace0 | +0
> one_of | "(123,456,789)\n (000,111,22~~~2)\n
> any | "(123,456,789)\n (000,111,22~~~2)\n
< any | +1
| verify |
< one_of | +1
> multispace0 | "123,456,789)\n (000,111,22~~~2)\n
> take_while | "123,456,789)\n (000,111,22~~~2)\n
< take_while | +0
< multispace0 | +0
> repeat | "123,456,789)\n (000,111,22~~~2)\n
> digit1 | "123,456,789)\n (000,111,22~~~2)\n
> take_while | "123,456,789)\n (000,111,22~~~2)\n
< take_while | +3
< digit1 | +3
> opt | ",456,789)\n (000,111,22~~~2)\n
> tag | ",456,789)\n (000,111,22~~~2)\n
< tag | +1
< opt | +1
> digit1 | "456,789)\n (000,111,22~~~2)\n "
> take_while | "456,789)\n (000,111,22~~~2)\n "
< take_while | +3
< digit1 | +3
> opt:1 | ",789)\n (000,111,22~~~2)\n "∅
> tag | ",789)\n (000,111,22~~~2)\n "∅
< tag | +1
< opt:1 | +1
> digit1 | "789)\n (000,111,22~~~2)\n "∅
> take_while | "789)\n (000,111,22~~~2)\n "∅
< take_while | +3
< digit1 | +3
> opt:2 | ")\n (000,111,22~~~2)\n "∅
> tag | ")\n (000,111,22~~~2)\n "∅
< tag | backtrack
< opt:2 | +0
> digit1 | ")\n (000,111,22~~~2)\n "∅
> take_while | ")\n (000,111,22~~~2)\n "∅
< take_while | backtrack
< digit1 | backtrack
< repeat | +11
> multispace0 | ")\n (000,111,22~~~2)\n "∅
> take_while | ")\n (000,111,22~~~2)\n "∅
< take_while | +0
< multispace0 | +0
> one_of | ")\n (000,111,22~~~2)\n "∅
> any | ")\n (000,111,22~~~2)\n "∅
< any | +1
| verify |
< one_of | +1
> multispace0 | "\n (000,111,22~~~2)\n "∅
> take_while | "\n (000,111,22~~~2)\n "∅
< take_while | +5
< multispace0 | +5
< delimited | +18
> delimited | "(000,111,22~~~2)\n "∅
> multispace0 | "(000,111,22~~~2)\n "∅
> take_while | "(000,111,22~~~2)\n "∅
< take_while | +0
< multispace0 | +0
> one_of | "(000,111,22~~~2)\n "∅
> any | "(000,111,22~~~2)\n "∅
< any | +1
| verify |
< one_of | +1
> multispace0 | "000,111,22~~~2)\n "∅
> take_while | "000,111,22~~~2)\n "∅
< take_while | +0
< multispace0 | +0
> repeat | "000,111,22~~~2)\n "∅
> digit1 | "000,111,22~~~2)\n "∅
> take_while | "000,111,22~~~2)\n "∅
< take_while | +3
< digit1 | +3
> opt | ",111,22~~~2)\n "∅
> tag | ",111,22~~~2)\n "∅
< tag | +1
< opt | +1
> digit1 | "111,22~~~2)\n "∅
> take_while | "111,22~~~2)\n "∅
< take_while | +3
< digit1 | +3
> opt:1 | ",22~~~2)\n "∅
> tag | ",22~~~2)\n "∅
< tag | +1
< opt:1 | +1
> digit1 | "22~~~2)\n "∅
> take_while | "22~~~2)\n "∅
< take_while | +2
< digit1 | +2
> opt:2 | "~~~2)\n "∅
> tag | "~~~2)\n "∅
< tag | backtrack
< opt:2 | +0
> digit1 | "~~~2)\n "∅
> take_while | "~~~2)\n "∅
< take_while | backtrack
< digit1 | backtrack
< repeat | +10
> multispace0 | "~~~2)\n "∅
> take_while | "~~~2)\n "∅
< take_while | +0
< multispace0 | +0
> one_of | "~~~2)\n "∅
> any | "~~~2)\n "∅
< any | +1
| verify | backtrack
< one_of | backtrack
< delimited | backtrack
< repeat | +18
> multispace0 | "(000,111,22~~~2)\n "∅
> take_while | "(000,111,22~~~2)\n "∅
< take_while | +0
< multispace0 | +0
< delimited | +18
> eof | "(000,111,22~~~2)\n "∅
< eof | backtrackWhat you need to do is to add cut_err calls for where it should disable backtracking. Likely this would be on the repeat inside of digit_group and the closing delimiter.
baoyachi
Please complete the following tasks
rust version
rustc 1.74.0 (79e9716c9 2023-11-13)
winnow version
0.5.34
Minimal reproducible code
Steps to reproduce the bug with the above code
cargo run
Actual Behaviour
Offset always returns 18
input1andinput2unexpectedly returned to the same position, which should be a bug.Expected Behaviour
Should return true offset
Additional Context
No response