radix.go
func (t *Tree) WalkPath(path string, fn WalkFn) {
	n := t.root
	search := path
	for {
		// Visit the leaf values if any
		if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
			return
		}

		// Check for key exhaution
		if len(search) == 0 {
			return
		}

		// Look for an edge
		n = n.getEdge(search[0])
		if n == nil {
			return
		}

		// Consume the search prefix
		if strings.HasPrefix(search, n.prefix) {
			search = search[len(n.prefix):]
		} else {
			break
		}
	}
}
func (t *Tree) WalkPath(path string, fn WalkFn) {
	n := t.root
	search := path
	for {
		// Visit the leaf values if any
		if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
			return
		}

		// Check for key exhaution
		if len(search) == 0 {
			return
		}

		// Look for an edge
		n = n.getEdge(search[0])
		if n == nil {
			return
		}

		// Consume the search prefix
		if strings.HasPrefix(search, n.prefix) {
			search = search[len(n.prefix):]
		} else {
			break
		}
	}
}
// WalkPath is used to walk the tree, but only visiting nodes
// from the root down to a given leaf. Where WalkPrefix walks
// all the entries *under* the given prefix, this walks the
// entries *above* the given prefix.