Method parse_query_body_seeded

src/sql-parser/src/parser.rs:7760–7800

(
        &mut self,
        precedence: SetPrecedence,
        mut expr: SetExpr<Raw>,
    )

    }

    fn parse_query_body_seeded(
        &mut self,
        precedence: SetPrecedence,
        mut expr: SetExpr<Raw>,
    ) -> Result<SetExpr<Raw>, ParserError> {
        loop {
            // The query can be optionally followed by a set operator:
            let next_token = self.peek_token();
            let op = self.parse_set_operator(&next_token);
            let next_precedence = match op {
                // UNION and EXCEPT have the same precedence and evaluate left-to-right
                Some(SetOperator::Union) | Some(SetOperator::Except) => SetPrecedence::UnionExcept,
                // INTERSECT has higher precedence than UNION/EXCEPT
                Some(SetOperator::Intersect) => SetPrecedence::Intersect,
                // Unexpected token or EOF => stop parsing the query body
                None => break,
            };
            if precedence >= next_precedence {
                break;
            }
            self.next_token(); // skip past the set operator

            let all = self.parse_keyword(ALL);
            let distinct = self.parse_keyword(DISTINCT);
            if all && distinct {
                return parser_err!(
                    self,
                    self.peek_prev_pos(),
                    "Cannot specify both ALL and DISTINCT in set operation"
                );
            }
            expr = SetExpr::SetOperation {
                left: Box::new(expr),
                op: op.unwrap(),
                all,
                right: Box::new(self.parse_query_body(next_precedence)?),
            };
        }

        Ok(expr)
    }

    fn parse_set_operator(&self, token: &Option<Token>) -> Option<SetOperator> {
        match token {