First iteration of the immutable AVL tree

merkle/types.go

@@ -0,0 +1,38 @@
+package merkle
+
+import (
+    "fmt"
+)
+
+type Sortable interface {
+    Equals(b Sortable) bool
+    Less(b Sortable) bool
+}
+
+type Tree interface {
+    Root() Node
+
+    Size() int
+    Has(key Sortable) bool
+    Get(key Sortable) (value interface{}, err error)
+
+    Put(key Sortable, value interface{}) (err error)
+    Remove(key Sortable) (value interface{}, err error)
+}
+
+type Node interface {
+    Key() Sortable
+    Value() interface{}
+    Left() Node
+    Right() Node
+
+    Size() int
+    Has(key Sortable) bool
+    Get(key Sortable) (value interface{}, err error)
+}
+
+type NodeIterator func() (node Node, next NodeIterator)
+
+func NotFound(key Sortable) error {
+    return fmt.Errorf("Key was not found.")
+}