Method try_parse_vector_matching

nodedb/src/control/promql/parser.rs:369–396

(&mut self)

    }

    fn try_parse_vector_matching(&mut self) -> Result<Option<VectorMatching>, PromqlError> {
        let has_on = self.try_keyword("on");
        let has_ignoring = !has_on && self.try_keyword("ignoring");
        if !has_on && !has_ignoring {
            return Ok(None);
        }
        let labels = self.parse_label_list()?;
        let mut matching = VectorMatching {
            card: MatchCard::OneToOne,
            on: if has_on { labels.clone() } else { vec![] },
            ignoring: if has_ignoring { labels } else { vec![] },
            group_left: vec![],
            group_right: vec![],
        };

        if self.try_keyword("group_left") {
            matching.card = MatchCard::ManyToOne;
            if matches!(self.peek(), Token::LParen) {
                matching.group_left = self.parse_label_list()?;
            }
        } else if self.try_keyword("group_right") {
            matching.card = MatchCard::OneToMany;
            if matches!(self.peek(), Token::LParen) {
                matching.group_right = self.parse_label_list()?;
            }
        }
        Ok(Some(matching))
    }

    fn try_parse_set_matching(&mut self) -> Result<Option<VectorMatching>, PromqlError> {
        let has_on = self.try_keyword("on");