radix.go
func (t *Tree) LongestPrefix(s string) (string, interface{}, bool) {
	var last *leafNode
	n := t.root
	search := s
	for {
		// Look for a leaf node
		if n.isLeaf() {
			last = n.leaf
		}

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

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

		// Consume the search prefix
		if strings.HasPrefix(search, n.prefix) {
			search = search[len(n.prefix):]
		} else {
			break
		}
	}
	if last != nil {
		return last.key, last.val, true
	}
	return "", nil, false
}
func (t *Tree) LongestPrefix(s string) (string, interface{}, bool) {
	var last *leafNode
	n := t.root
	search := s
	for {
		// Look for a leaf node
		if n.isLeaf() {
			last = n.leaf
		}

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

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

		// Consume the search prefix
		if strings.HasPrefix(search, n.prefix) {
			search = search[len(n.prefix):]
		} else {
			break
		}
	}
	if last != nil {
		return last.key, last.val, true
	}
	return "", nil, false
}
// LongestPrefix is like Get, but instead of an
// exact match, it will return the longest prefix match.