unable to bypass negatives

[shi-yan]

I have the following grammar

sequence_body = {sequence_begin ~ NEWLINE+ ~ (!sequence_end ~ sequence_line ~ NEWLINE+)* ~ sequence_end}

I expect it to match the following:

sequence_begin
sequence_line
sequence_line
sequence_line
sequence_line
...
sequence_end

because sequence_line starts with ASCII_ALPHA+, and sequence_end starts with "end", which is also ASCII_ALPHA+, I added !sequence_end

And I got the error:

unexpected sequence_end

it refers to the actual sequence_end

Error { variant: ParsingError { positives: [], negatives: [sequence_group_end] }, location: Pos(317), line_col: Pos((15, 9)), path: None, line: "        end␊", continued_line: None }'

(!sequence_end ~ line) * ~ sequence_end

if the parser hits the first !sequence_end, I would expect it to finish the ()* part and then match the second positive sequence_end.

but instead, it just generates an error.

plantumlparser.zip

the reproducible project is attached too.

[01mf02]

Hello,

I have tried to reproduce your problem.

I made the following grammar:

sequence_body = {sequence_begin ~ NEWLINE+ ~ (!sequence_end ~ sequence_line ~ NEWLINE+)* ~ sequence_end}
sequence_begin = {"begin"}
sequence_line = {"line"}
sequence_end = {"end"}

And the following program:

extern crate pest;
#[macro_use]
extern crate pest_derive;

use pest::Parser;

#[derive(Parser)]
#[grammar = "grammar.pest"]
pub struct SeqParser;

const SEQ: &str =
"begin
line
line
end
";

fn main() {
    let parse = SeqParser::parse(Rule::sequence_body, SEQ);
    match parse {
        Err(e) => println!("error: {}", e),
        Ok(_) => println!("done"),
    }
}

However, this seems to work fine.
So perhaps it might help you to adapt my example until you experience your error?