Method apply

datafusion/common/src/tree_node.rs:196–209

Applies `f` to the node then each of its children, recursively (a top-down, pre-order traversal). The return [`TreeNodeRecursion`] controls the recursion and can cause an early return. # See Also [`Self::transform_down`] for the equivalent transformation API. [`Self::visit`] for both top-down and bottom up traversal.

(
        &'n self,
        mut f: F,
    )

    /// * [`Self::transform_down`] for the equivalent transformation API.
    /// * [`Self::visit`] for both top-down and bottom up traversal.
    fn apply<'n, F: FnMut(&'n Self) -> Result<TreeNodeRecursion>>(
        &'n self,
        mut f: F,
    ) -> Result<TreeNodeRecursion> {
        #[cfg_attr(feature = "recursive_protection", recursive::recursive)]
        fn apply_impl<'n, N: TreeNode, F: FnMut(&'n N) -> Result<TreeNodeRecursion>>(
            node: &'n N,
            f: &mut F,
        ) -> Result<TreeNodeRecursion> {
            f(node)?.visit_children(|| node.apply_children(|c| apply_impl(c, f)))
        }

        apply_impl(self, &mut f)
    }

    /// Recursively rewrite the node's children and then the node using `f`
    /// (a bottom-up post-order traversal).