difftree: merkletrie internal package with iterator (#133)

1 files changed, 20 insertions, 0 deletions

diff --git a/difftree/internal/radixmerkle/noder.go b/difftree/internal/radixmerkle/noder.go
new file mode 100644
index 0000000..3566657
--- /dev/null
+++ b/difftree/internal/radixmerkle/noder.go
@@ -0,0 +1,20 @@
+package merkletrie
+
+// The Noder interface is implemented by the elements of a Merkle Trie.
+type Noder interface {
+	// Hash returns the hash of the element.
+	Hash() []byte
+	// Key returns the key of the element.
+	Key() string
+	// Children returns the children of the element, sorted
+	// in reverse key alphabetical order.
+	Children() []Noder
+	// NumChildren returns the number of children this element has.
+	//
+	// This method is an optimization: the number of children is easily
+	// calculated as the length of the value returned by the Children
+	// method (above); yet, some implementations will be able to
+	// implement NumChildren in O(1) while Children is usually more
+	// complex.
+	NumChildren() int
+}