Method update_ranges

datafusion/physical-expr/src/intervals/cp_solver.rs:510–533

Updates intervals for all expressions in the DAEG by successive bottom-up and top-down traversals.

(
        &mut self,
        leaf_bounds: &mut [(usize, Interval)],
        given_range: Interval,
    )

    /// Updates intervals for all expressions in the DAEG by successive
    /// bottom-up and top-down traversals.
    pub fn update_ranges(
        &mut self,
        leaf_bounds: &mut [(usize, Interval)],
        given_range: Interval,
    ) -> Result<PropagationResult> {
        self.assign_intervals(leaf_bounds);
        let bounds = self.evaluate_bounds()?;
        // There are three possible cases to consider:
        // (1) given_range ⊇ bounds => Nothing to propagate
        // (2) ∅ ⊂ (given_range ∩ bounds) ⊂ bounds => Can propagate
        // (3) Disjoint sets => Infeasible
        if given_range.contains(bounds)? == Interval::TRUE {
            // First case:
            Ok(PropagationResult::CannotPropagate)
        } else if bounds.contains(&given_range)? != Interval::FALSE {
            // Second case:
            let result = self.propagate_constraints(given_range);
            self.update_intervals(leaf_bounds);
            result
        } else {
            // Third case:
            Ok(PropagationResult::Infeasible)
        }
    }

    /// This function assigns given ranges to expressions in the DAEG.
    /// The argument `assignments` associates indices of sought expressions