Method get_next_precedence

src/sql-parser/src/parser.rs:1682–1722

Get the precedence of the next token

(&self)

    /// Get the precedence of the next token
    fn get_next_precedence(&self) -> Precedence {
        if let Some(token) = self.peek_token() {
            match &token {
                Token::Keyword(OR) => Precedence::Or,
                Token::Keyword(AND) => Precedence::And,
                Token::Keyword(NOT) => match &self.peek_nth_token(1) {
                    // The precedence of NOT varies depending on keyword that
                    // follows it. If it is followed by IN, BETWEEN, or LIKE,
                    // it takes on the precedence of those tokens. Otherwise it
                    // is not an infix operator, and therefore has zero
                    // precedence.
                    Some(Token::Keyword(IN)) => Precedence::Like,
                    Some(Token::Keyword(BETWEEN)) => Precedence::Like,
                    Some(Token::Keyword(ILIKE)) => Precedence::Like,
                    Some(Token::Keyword(LIKE)) => Precedence::Like,
                    _ => Precedence::Zero,
                },
                Token::Keyword(IS) | Token::Keyword(ISNULL) => Precedence::Is,
                Token::Keyword(IN) => Precedence::Like,
                Token::Keyword(BETWEEN) => Precedence::Like,
                Token::Keyword(ILIKE) => Precedence::Like,
                Token::Keyword(LIKE) => Precedence::Like,
                Token::Keyword(OPERATOR) => Precedence::Other,
                Token::Op(s) => match s.as_str() {
                    "<" | "<=" | "<>" | "!=" | ">" | ">=" => Precedence::Cmp,
                    "+" | "-" => Precedence::PlusMinus,
                    "/" | "%" => Precedence::MultiplyDivide,
                    _ => Precedence::Other,
                },
                Token::Eq => Precedence::Cmp,
                Token::Star => Precedence::MultiplyDivide,
                Token::Keyword(COLLATE) | Token::Keyword(AT) => Precedence::PostfixCollateAt,
                Token::DoubleColon | Token::LBracket | Token::Dot => {
                    Precedence::PostfixSubscriptCast
                }
                _ => Precedence::Zero,
            }
        } else {
            Precedence::Zero
        }
    }

    /// Return the first non-whitespace token that has not yet been processed
    /// (or None if reached end-of-file)