Method len_recursive

rust/src/tree_structure.rs:20–34

Recursively count elements with proper arena access.

(&self, node: &NodeRef<K, V>)

    /// Recursively count elements with proper arena access.
    fn len_recursive(&self, node: &NodeRef<K, V>) -> usize {
        match node {
            NodeRef::Leaf(id, _) => self.get_leaf(*id).map(|leaf| leaf.len()).unwrap_or(0),
            NodeRef::Branch(id, _) => self
                .get_branch(*id)
                .map(|branch| {
                    branch
                        .children
                        .iter()
                        .map(|child| self.len_recursive(child))
                        .sum()
                })
                .unwrap_or(0),
        }
    }

    /// Returns true if the tree is empty.
    pub fn is_empty(&self) -> bool {