func (self *TST) PrefixFind(prefix ByteSlice) KVIterator {
if len(prefix) == 0 {
return self.Iterate()
}
type entry struct {
n *TSTNode
d int
}
var root *TSTNode = nil
next := &entry{self.heads[prefix[0]], 1}
for {
if next.n == nil {
break
} else if next.n.Internal() {
if next.d == len(prefix) {
root = next.n
break
}
ch := prefix[next.d]
if ch < next.n.ch {
next = &entry{next.n.l, next.d}
} else if ch == next.n.ch {
next = &entry{next.n.m, next.d + 1}
} else if ch > next.n.ch {
next = &entry{next.n.r, next.d}
}
} else if next.n.accepting && next.n.key[:len(prefix)].Equals(prefix) {
root = next.n
break
} else {
break
}
}
if root == nil {
return func() (Hashable, interface{}, KVIterator) {
return nil, nil, nil
}
}
tni := tree.TraverseTreePreOrder(root)
var kv_iterator KVIterator
kv_iterator = func() (key Hashable, value interface{}, next KVIterator) {
var tn TreeNode
for {
tn, tni = tni()
if tni == nil {
return nil, nil, nil
}
n := tn.(*TSTNode)
if n.accepting {
return n.key[:len(n.key)-1], n.value, kv_iterator
}
}
}
return kv_iterator
}
func TestTraversals(t *testing.T) {
var data []int = []int{
1, 5, 7, 9, 12, 13, 17, 18, 19, 20,
}
var order []int = []int{
6, 1, 8, 2, 4, 9, 5, 7, 0, 3,
}
var preorder []int = []int{
17, 7, 5, 1, 12, 9, 13, 19, 18, 20,
}
var postorder []int = []int{
1, 5, 9, 13, 12, 7, 18, 20, 19, 17,
}
test := func(T types.TreeMap) {
t.Logf("%T", T)
for j := range order {
if err := T.Put(types.Int(data[order[j]]), order[j]); err != nil {
t.Error(err)
}
}
j := 0
for tn, next := tree.TraverseBinaryTreeInOrder(T.Root().(types.BinaryTreeNode))(); next != nil; tn, next = next() {
if int(tn.Key().(types.Int)) != data[j] {
t.Error("key in wrong spot in-order")
}
j += 1
}
j = 0
for tn, next := tree.TraverseTreePreOrder(T.Root())(); next != nil; tn, next = next() {
if int(tn.Key().(types.Int)) != preorder[j] {
t.Error("key in wrong spot pre-order")
}
j += 1
}
j = 0
for tn, next := tree.TraverseTreePostOrder(T.Root())(); next != nil; tn, next = next() {
if int(tn.Key().(types.Int)) != postorder[j] {
t.Error("key in wrong spot post-order")
}
j += 1
}
}
test(NewAvlTree())
test(NewImmutableAvlTree())
}
func (self *TST) Iterate() KVIterator {
tnis := make([]TreeNodeIterator, 0, 256)
for _, n := range self.heads {
if n != nil {
tnis = append(tnis, tree.TraverseTreePreOrder(n))
}
}
tni := ChainTreeNodeIterators(tnis...)
var kv_iterator KVIterator
kv_iterator = func() (key Hashable, value interface{}, next KVIterator) {
var tn TreeNode
for {
tn, tni = tni()
if tni == nil {
return nil, nil, nil
}
n := tn.(*TSTNode)
if n.accepting {
return n.key[:len(n.key)-1], n.value, kv_iterator
}
}
}
return kv_iterator
}