Method lookup

src/expr/src/relation.rs:1664–1677

Return: every row in keys_and_values every row in `self` that does not have a matching row in the first columns of `keys_and_values`, using `default` to fill in the remaining columns (This is LEFT OUTER JOIN if: 1) `default` is a row of null 2) matching rows in `keys_and_values` and `self` have the same multiplicity.)

(
        self,
        id_gen: &mut IdGen,
        keys_and_values: MirRelationExpr,
        default: Vec<(Datum<'static>, ReprScalarType)>,
    )

    /// 1) `default` is a row of null
    /// 2) matching rows in `keys_and_values` and `self` have the same multiplicity.)
    pub fn lookup<E>(
        self,
        id_gen: &mut IdGen,
        keys_and_values: MirRelationExpr,
        default: Vec<(Datum<'static>, ReprScalarType)>,
    ) -> Result<MirRelationExpr, E> {
        keys_and_values.let_in(id_gen, |id_gen, get_keys_and_values| {
            Ok(get_keys_and_values.clone().union(self.anti_lookup(
                id_gen,
                get_keys_and_values,
                default,
            )?))
        })
    }

    /// True iff the expression contains a `NullaryFunc::MzLogicalTimestamp`.
    pub fn contains_temporal(&self) -> bool {