Method parse_postfix

nodedb/src/control/promql/parser.rs:107–152

(&mut self)

    }

    fn parse_postfix(&mut self) -> Result<Expr, PromqlError> {
        let mut expr = self.parse_primary()?;

        if matches!(self.peek(), Token::LBracket) {
            self.advance();
            let range = self.parse_duration()?;
            let step = if matches!(self.peek(), Token::Colon) {
                self.advance();
                if matches!(self.peek(), Token::RBracket) {
                    None
                } else {
                    Some(self.parse_duration()?)
                }
            } else {
                None
            };
            self.expect(&Token::RBracket)?;

            if step.is_some() || !matches!(expr, Expr::VectorSelector { .. }) {
                expr = Expr::Subquery {
                    expr: Box::new(expr),
                    range,
                    step,
                };
            } else {
                expr = Expr::MatrixSelector {
                    selector: Box::new(expr),
                    range,
                };
            }
        }

        if self.try_keyword("offset") {
            let neg = matches!(self.peek(), Token::Sub);
            if neg {
                self.advance();
            }
            let mut dur = self.parse_duration()?;
            if neg {
                dur = Duration(-dur.ms());
            }
            expr = apply_offset(expr, dur);
        }

        Ok(expr)
    }

    fn parse_primary(&mut self) -> Result<Expr, PromqlError> {
        match self.peek().clone() {