iowo/crates/json-pawarser/src/grammar/array.rs

use crate::{syntax_error::SyntaxError, syntax_kind::SyntaxKind};

use super::{value, CompletedMarker, Parser};

pub(super) fn array(p: &mut Parser) -> Option<CompletedMarker> {
    let array_start = p.start("array");

    if !p.eat(SyntaxKind::BRACKET_OPEN) {
        array_start.abandon(p);
        return None;
    }

    let el = p.start("arr_el");
    value(p);
    el.complete(p, SyntaxKind::ELEMENT);

    while p.at(SyntaxKind::COMMA) {
        let potential_trailing_comma = p.start("potential_trailing_comma");

        p.eat(SyntaxKind::COMMA);
        let maybe_el = p.start("arr_el");
        if !value(p) {
            maybe_el.abandon(p);
            potential_trailing_comma.complete(p, SyntaxKind::TRAILING_COMMA);
        } else {
            maybe_el.complete(p, SyntaxKind::ELEMENT);
            potential_trailing_comma.abandon(p);
        }
    }

    Some(if !p.eat(SyntaxKind::BRACKET_CLOSE) {
        array_start.error(p, SyntaxError::UnclosedArray)
    } else {
        array_start.complete(p, SyntaxKind::ARRAY)
    })
}

#[cfg(test)]
mod tests {
    use crate::grammar::{array::array, test_utils::gen_checks};

    #[test]
    fn array_basic() {
        gen_checks! {array;
            r#"[1,2,3]"# => r#"ROOT { ARRAY { BRACKET_OPEN "["; ELEMENT { NUMBER "1"; } COMMA ","; ELEMENT { NUMBER "2"; } COMMA ","; ELEMENT { NUMBER "3"; } BRACKET_CLOSE "]"; } }"#,
            r#"[1,2,]"# => r#"ROOT { ARRAY { BRACKET_OPEN "["; ELEMENT { NUMBER "1"; } COMMA ","; ELEMENT { NUMBER "2"; } TRAILING_COMMA { COMMA ","; } BRACKET_CLOSE "]"; } }"#,
            r#"[1,2"# => r#"ROOT { PARSE_ERR: UnclosedArray { BRACKET_OPEN "["; ELEMENT { NUMBER "1"; } COMMA ","; ELEMENT { NUMBER "2"; } } }"#,
            r#"[1,2,"# => r#"ROOT { PARSE_ERR: UnclosedArray { BRACKET_OPEN "["; ELEMENT { NUMBER "1"; } COMMA ","; ELEMENT { NUMBER "2"; } TRAILING_COMMA { COMMA ","; } } }"#,
            r#"[{"hello":"world""# => r#"ROOT { PARSE_ERR: UnclosedArray { BRACKET_OPEN "["; ELEMENT { PARSE_ERR: UnclosedObject { BRACE_OPEN "{"; MEMBER { MEMBER_NAME { STRING "\"hello\""; } COLON ":"; MEMBER_VALUE { STRING "\"world\""; } } } } } }"#
        }
    }
}