From c3257436c7d4c10a0ba0874d054b7e7bddffe7e5 Mon Sep 17 00:00:00 2001
From: michaelvlach <vlach.michael@gmail.com>
Date: Thu, 22 Sep 2022 21:13:23 +0200
Subject: [PATCH 1/4] Create graph_node_iterator.rs

---
 src/graph/graph_node_iterator.rs | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 src/graph/graph_node_iterator.rs

diff --git a/src/graph/graph_node_iterator.rs b/src/graph/graph_node_iterator.rs
new file mode 100644
index 00000000..6f9b2a47
--- /dev/null
+++ b/src/graph/graph_node_iterator.rs
@@ -0,0 +1,23 @@
+use super::graph_node::GraphNode;
+use super::Graph;
+
+pub(crate) struct GraphNodeIterator<'a> {
+    pub(crate) graph: &'a Graph,
+    pub(crate) index: i64,
+}
+
+impl<'a> Iterator for GraphNodeIterator<'a> {
+    type Item = GraphNode<'a>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if let Some(next) = self.graph.next_node(self.index) {
+            self.index = next;
+            return Some(GraphNode {
+                graph: self.graph,
+                index: self.index,
+            });
+        }
+
+        None
+    }
+}

From 5355c8a9394ddb22f90b0ee3edb16b7ca86a2d42 Mon Sep 17 00:00:00 2001
From: michaelvlach <vlach.michael@gmail.com>
Date: Thu, 22 Sep 2022 21:13:26 +0200
Subject: [PATCH 2/4] Update graph_node.rs

---
 src/graph/graph_node.rs | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/graph/graph_node.rs b/src/graph/graph_node.rs
index 136325f7..c436a354 100644
--- a/src/graph/graph_node.rs
+++ b/src/graph/graph_node.rs
@@ -1,12 +1,14 @@
-#[allow(dead_code)]
-pub(crate) struct GraphNode {}
+use super::Graph;
 
-#[cfg(test)]
-mod tests {
-    use super::*;
+#[allow(dead_code)]
+pub(crate) struct GraphNode<'a> {
+    pub(crate) graph: &'a Graph,
+    pub(crate) index: i64,
+}
 
-    #[test]
-    fn new() {
-        let _node = GraphNode {};
+#[allow(dead_code)]
+impl<'a> GraphNode<'a> {
+    pub(crate) fn index(&self) -> i64 {
+        self.index
     }
 }

From 17957635bc6b93b3ff9d1cf399e1c5829179987f Mon Sep 17 00:00:00 2001
From: michaelvlach <vlach.michael@gmail.com>
Date: Thu, 22 Sep 2022 21:13:29 +0200
Subject: [PATCH 3/4] Update graph.rs

---
 src/graph.rs | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/graph.rs b/src/graph.rs
index 46e9020e..8a6e858c 100644
--- a/src/graph.rs
+++ b/src/graph.rs
@@ -1,8 +1,10 @@
+use self::graph_node_iterator::GraphNodeIterator;
 use crate::DbError;
 
 mod graph_edge;
 mod graph_element;
 mod graph_node;
+mod graph_node_iterator;
 
 pub(crate) struct Graph {
     from: Vec<i64>,
@@ -52,6 +54,23 @@ impl Graph {
         self.node_count as i64
     }
 
+    pub(crate) fn node_iter(&self) -> GraphNodeIterator {
+        GraphNodeIterator {
+            graph: self,
+            index: 0,
+        }
+    }
+
+    fn next_node(&self, index: i64) -> Option<i64> {
+        for i in (index as usize + 1)..self.from_meta.len() {
+            if 0 <= self.from_meta[i] {
+                return Some(i as i64);
+            }
+        }
+
+        None
+    }
+
     fn validate_node(&self, index: i64) -> Result<(), DbError> {
         if let Some(meta) = self.from_meta.get(index as usize) {
             if 0 <= *meta {
@@ -117,4 +136,21 @@ mod tests {
 
         assert_eq!(id, 1);
     }
+
+    #[test]
+    fn node_iteration() {
+        let mut graph = Graph::new();
+        let expected = vec![
+            graph.insert_node(),
+            graph.insert_node(),
+            graph.insert_node(),
+        ];
+        let mut nodes = Vec::<i64>::new();
+
+        for node in graph.node_iter() {
+            nodes.push(node.index());
+        }
+
+        assert_eq!(nodes, expected);
+    }
 }

From f66a2f409a3d9e37f2a26019dcd09b246450aaee Mon Sep 17 00:00:00 2001
From: michaelvlach <vlach.michael@gmail.com>
Date: Thu, 22 Sep 2022 21:13:32 +0200
Subject: [PATCH 4/4] Update pr.yaml

---
 .github/workflows/pr.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/pr.yaml b/.github/workflows/pr.yaml
index 863fac94..76daf13d 100644
--- a/.github/workflows/pr.yaml
+++ b/.github/workflows/pr.yaml
@@ -44,7 +44,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: taiki-e/install-action@cargo-llvm-cov
       - run: rustup component add llvm-tools-preview
-      - run: cargo llvm-cov --fail-uncovered-regions 126 --fail-uncovered-functions 0 --fail-uncovered-lines 1
+      - run: cargo llvm-cov --fail-uncovered-regions 127 --fail-uncovered-functions 0 --fail-uncovered-lines 2
 
   test:
     runs-on: ubuntu-latest