Function exclude

prqlc/prqlc/src/sql/gen_projection.rs:72–81

When compiling: from employees | group department (take 3) Row number will be computed in a CTE that also contains a star. In the main query, star will also include row number, which was not requested. This function adds that column to the exclusion tuple.

(star: &mut Option<(CId, HashSet<CId>)>, excluded: &mut Excluded)

    // requested.
    // This function adds that column to the exclusion tuple.
    fn exclude(star: &mut Option<(CId, HashSet<CId>)>, excluded: &mut Excluded) {
        let Some((cid, in_star)) = star.take() else {
            return;
        };
        if in_star.is_empty() {
            return;
        }

        excluded.insert(cid, in_star);
    }

    let mut output = Vec::new();
    for cid in cols {