Tagged Tree

This crate provides a simple tree structure in which all the nodes (except the root) are tagged with an arbitrary type.

Example

```rust use tagged_tree::Tree;

fn main() { // create the tree with the root node let mut tree = Tree::<&'static str, i32>::new(42); assert_eq!(*tree.value(), 42);

// add the value 1 tagged with "hello"
let (old_val, child) = tree.add_child("hello", 1);
assert!(old_val.is_none());
assert_eq!(*child.value(), 1);

// replace it with 5
let (old_val, child) = tree.add_child("hello", 5);
assert_eq!(old_val.unwrap(), 1);
assert_eq!(*child.value(), 5);

// add a child to the child
child.add_child("world", 2);

// add another child to the original
tree.add_child("greetings", 3);

// iterate over the direct children
for (key, child) in tree.iter_single() {
    println!("{}: {}", key, child.value());
}

// depth first traversal
for (key, value) in tree.iter_depth_first() {
    println!("{}: {}", key, value);
}

// breadth first traversal
for (key, value) in tree.iter_breadth_first() {
    println!("{}: {}", key, value);
}

} ```