radix.go
func recursiveWalk(n *node, fn WalkFn) bool {
	// Visit the leaf values if any
	if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
		return true
	}

	// Recurse on the children
	for _, e := range n.edges {
		if recursiveWalk(e.node, fn) {
			return true
		}
	}
	return false
}
func recursiveWalk(n *node, fn WalkFn) bool {
	// Visit the leaf values if any
	if n.leaf != nil && fn(n.leaf.key, n.leaf.val) {
		return true
	}

	// Recurse on the children
	for _, e := range n.edges {
		if recursiveWalk(e.node, fn) {
			return true
		}
	}
	return false
}
// recursiveWalk is used to do a pre-order walk of a node
// recursively. Returns true if the walk should be aborted