Row-wise comparison operations about mammoth HOT 2 CLOSED

db
      .select(star())
      .from(db.foo)
      .where(raw`(name, value)`.gt(raw`(${'Test'}, ${123})`));

// Postgres has row-wise comparison syntax:
//     (a, b, c) > ($1, $2, $3)
// But Mammoth doesn't yet support it.  So this function generates the long version:
//     (a > $1) OR (a = $1 AND (b > $2 OR (b = $2 AND c > $3)))
// Not sure if the Postgres optimizer deals with this well.
export function rowWiseCompare<Columns extends Expression<any, true, string>[]>(
    comparisonFn: ComparisonFn,
    columns: [...Columns],
    values: ColumnValuesT<Columns>,
): DefaultExpression<boolean> {
    // Build it from right to left.
    let i = columns.length - 1;
    let expr = comparisonFn(columns[i], values[i]);
    while (i > 0) {
        i--;
        expr = comparisonFn(columns[i], values[i]).or(columns[i].eq(values[i]).and(expr));
    }
    return expr;
}

type ColumnValuesT<Columns extends unknown[]> = {[I in keyof Columns]: Columns[I] extends Expression<infer T, true, string> ? T : never};

export type ComparisonFn = <T>(
    expr: Expression<T, boolean, string>,
    value: T | Expression<T, boolean, any>,
) => DefaultExpression<boolean>;

export const gt: ComparisonFn = (e, v) => e.gt(v);
export const lt: ComparisonFn = (e, v) => e.lt(v);
export const gte: ComparisonFn = (e, v) => e.gte(v);
export const lte: ComparisonFn = (e, v) => e.lte(v);