Method swap

datafusion/expr-common/src/operator.rs:248–294

Return the operator where swapping lhs and rhs wouldn't change the result. For example `Binary(50, >=, a)` could also be represented as `Binary(a, <=, 50)`.

(&self)

    ///
    /// For example `Binary(50, >=, a)` could also be represented as `Binary(a, <=, 50)`.
    pub fn swap(&self) -> Option<Operator> {
        match self {
            Operator::Eq => Some(Operator::Eq),
            Operator::NotEq => Some(Operator::NotEq),
            Operator::Lt => Some(Operator::Gt),
            Operator::LtEq => Some(Operator::GtEq),
            Operator::Gt => Some(Operator::Lt),
            Operator::GtEq => Some(Operator::LtEq),
            Operator::AtArrow => Some(Operator::ArrowAt),
            Operator::ArrowAt => Some(Operator::AtArrow),
            Operator::IsDistinctFrom => Some(Operator::IsDistinctFrom),
            Operator::IsNotDistinctFrom => Some(Operator::IsNotDistinctFrom),
            Operator::Plus
            | Operator::Minus
            | Operator::Multiply
            | Operator::Divide
            | Operator::Modulo
            | Operator::And
            | Operator::Or
            | Operator::RegexMatch
            | Operator::RegexIMatch
            | Operator::RegexNotMatch
            | Operator::RegexNotIMatch
            | Operator::LikeMatch
            | Operator::ILikeMatch
            | Operator::NotLikeMatch
            | Operator::NotILikeMatch
            | Operator::BitwiseAnd
            | Operator::BitwiseOr
            | Operator::BitwiseXor
            | Operator::BitwiseShiftRight
            | Operator::BitwiseShiftLeft
            | Operator::StringConcat
            | Operator::Arrow
            | Operator::LongArrow
            | Operator::HashArrow
            | Operator::HashLongArrow
            | Operator::AtAt
            | Operator::IntegerDivide
            | Operator::HashMinus
            | Operator::AtQuestion
            | Operator::Question
            | Operator::QuestionAnd
            | Operator::QuestionPipe
            | Operator::Colon => None,
        }
    }

    /// Get the operator precedence
    /// use <https://www.postgresql.org/docs/7.2/sql-precedence.html> as a reference