implemented iterator that yields cloned blocks from a page

src/blocktree.rs

@@ -1,7 +1,7 @@
 
 use std::collections::HashMap;
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct NoteBlock {
     // IDs are int64 as this is the datatype of rowids in sqlite
     id: i128,
@@ -87,22 +87,41 @@ impl NotePage {
     }
 }
 
-struct NotePageIterator {
+struct NotePageIterator<'a> {
-    page: &NotePage,
+    page: &'a NotePage,
-    node_stack: Vec<&BlockTreeNode>
+    node_stack: Vec<&'a BlockTreeNode>
 }
 
-impl NotePageIterator {
+impl<'a> NotePageIterator<'a> {
-    fn new(page:
+    fn new(page: &'a NotePage) -> Self {
+        Self {
+            page: page,
+            node_stack: vec![&page.block_tree_root]
+        }
+    }
 }
 
-impl Iterator for NotePageIterator {
+impl<'a> Iterator for NotePageIterator<'a> {
     type Item = NoteBlock;
     fn next(&mut self) -> Option<Self::Item> {
-        // no existing iteration state, initialize with root node
-        if let None = self.iter_state {
 
+        // stack is empty, we are done otherwise continue with current_node
+        let Some(current_node) = self.node_stack.pop() else {
+            return None;
+        };
+
+        // if the current node has a next sibling, stack it.
+        if let Some(next_sibling_node) = &current_node.next_sibling_node {
+            self.node_stack.push(next_sibling_node);
         }
+
+        // if the current node has a first child, stack it.
+        if let Some(first_child_node) = &current_node.first_child_node {
+            self.node_stack.push(first_child_node);
+        }
+
+        // yield a clone of the block pointed to by current_node
+        Some(self.page.block_table.get(&current_node.block_id).unwrap().clone())
     }
 
 }