Method parse_optional_internal_as_of

src/sql-parser/src/parser.rs:8721–8739

Parse `AS OF`, if present. In contrast to `parse_optional_as_of`, this parser only supports `AS OF ` syntax and directly returns an `u64`. It is only meant to be used for internal SQL syntax.

(&mut self)

    /// In contrast to `parse_optional_as_of`, this parser only supports `AS OF <time>` syntax and
    /// directly returns an `u64`. It is only meant to be used for internal SQL syntax.
    fn parse_optional_internal_as_of(&mut self) -> Result<Option<u64>, ParserError> {
        fn try_parse_u64(parser: &mut Parser) -> Option<u64> {
            let value = parser.parse_value().ok()?;
            let Value::Number(s) = value else { return None };
            s.parse().ok()
        }

        if self.parse_keywords(&[AS, OF]) {
            match try_parse_u64(self) {
                Some(time) => Ok(Some(time)),
                None => {
                    self.prev_token();
                    self.expected(self.peek_pos(), "`u64` literal", self.peek_token())
                }
            }
        } else {
            Ok(None)
        }
    }

    /// Parse a comma-delimited list of projections after SELECT
    fn parse_select_item(&mut self) -> Result<SelectItem<Raw>, ParserError> {