Method implement

src/plan/antijoin.rs:47–105

(
        &self,
        nested: &mut Iterative<'b, S, u64>,
        local_arrangements: &VariableMap<Iterative<'b, S, u64>>,
        context: &mut I,
    )

    }

    fn implement<'b, T, I, S>(
        &self,
        nested: &mut Iterative<'b, S, u64>,
        local_arrangements: &VariableMap<Iterative<'b, S, u64>>,
        context: &mut I,
    ) -> (Implemented<'b, S>, ShutdownHandle)
    where
        T: Timestamp + Lattice,
        I: ImplContext<T>,
        S: Scope<Timestamp = T>,
    {
        let mut shutdown_handle = ShutdownHandle::empty();
        let left = {
            let (left, shutdown) = self
                .left_plan
                .implement(nested, local_arrangements, context);
            shutdown_handle.merge_with(shutdown);
            left
        };
        let right = {
            let (right, shutdown) = self
                .right_plan
                .implement(nested, local_arrangements, context);
            shutdown_handle.merge_with(shutdown);
            right
        };

        let variables = self
            .variables
            .iter()
            .cloned()
            .chain(
                left.variables()
                    .drain(..)
                    .filter(|x| !self.variables.contains(x)),
            )
            .collect();

        let right_projected = {
            let (projected, shutdown) = right.projected(nested, context, &self.variables);
            shutdown_handle.merge_with(shutdown);
            projected
        };

        let left_arranged = {
            let (arranged, shutdown) = left.tuples_by_variables(nested, context, &self.variables);
            shutdown_handle.merge_with(shutdown);
            arranged
        };

        let tuples = left_arranged
            .distinct()
            .antijoin(&right_projected.distinct())
            .map(|(key, tuple)| key.iter().cloned().chain(tuple.iter().cloned()).collect());

        let relation = CollectionRelation { variables, tuples };

        (Implemented::Collection(relation), shutdown_handle)