Change "neighbor" terminology to "adjacent vertex" throughout the code

src/algorithms.rs

@@ -33,8 +33,8 @@ where
     W: Fn(G::Edge) -> u32,
 {
     let mut predecessors = graph.vertex_map(None);
-    let distances = dijkstra_impl(graph, source, weight, |neighbor, predecessor| {
+    let distances = dijkstra_impl(graph, source, weight, |adjacent, predecessor| {
-        predecessors[neighbor] = Some(predecessor);
+        predecessors[adjacent] = Some(predecessor);
     });
     DijkstraResult {
         distances,
@@ -92,19 +92,19 @@ where
     });
 
     while let Some(v) = heap.pop() {
-        for neighbor in graph.neighbors(v.vertex) {
+        for adjacent in graph.adjacent_vertices(v.vertex) {
             // TODO: Use custom edge weights in Dijkstra's algorithm.
             let edge_weight = 1;
             let new_distance = distances[v.vertex].unwrap() + edge_weight;
-            if match distances[neighbor] {
+            if match distances[adjacent] {
                 None => true,
                 Some(old_distance) if old_distance > new_distance => true,
                 _ => false,
             } {
-                distances[neighbor] = Some(new_distance);
+                distances[adjacent] = Some(new_distance);
-                on_relax(neighbor, v.vertex);
+                on_relax(adjacent, v.vertex);
                 heap.push(DistanceOrderedVertex {
-                    vertex: neighbor,
+                    vertex: adjacent,
                     distance: new_distance,
                 });
             }

src/models/append_graph.rs

@@ -20,22 +20,22 @@ struct VertexIncidenceHeader {
 
 struct IncidenceEntry {
     next: Option<Incidence>,
-    neighbor: Vertex,
+    adjacent: Vertex,
 }
 
-struct VertexNeighborIterator<'a> {
+struct VertexAdjacenceIterator<'a> {
     graph: &'a AppendGraph,
     incidence: Option<Incidence>,
 }
 
-impl<'a> Iterator for VertexNeighborIterator<'a> {
+impl<'a> Iterator for VertexAdjacenceIterator<'a> {
     type Item = Vertex;
 
     fn next(&mut self) -> Option<Self::Item> {
         let incidence = self.incidence?;
         let entry = &self.graph.incidences[incidence.0];
         self.incidence = entry.next;
-        Some(entry.neighbor)
+        Some(entry.adjacent)
     }
 }
 
@@ -58,7 +58,7 @@ impl AppendGraph {
     fn add_incidence(&mut self, v1: Vertex, v2: Vertex) {
         self.incidences.push(IncidenceEntry {
             next: self.vertices[v1.0].first_incidence.take(),
-            neighbor: v2,
+            adjacent: v2,
         });
         self.vertices[v1.0].incidence_count += 1;
         self.vertices[v1.0].first_incidence = Some(Incidence(self.incidences.len() - 1));
@@ -105,15 +105,15 @@ impl GraphTopology for AppendGraph {
     }
 
     fn are_adjacent(&self, v1: Self::Vertex, v2: Self::Vertex) -> bool {
-        self.neighbors(v1).any(|x| x == v2)
+        self.adjacent_vertices(v1).any(|x| x == v2)
     }
 
     fn vertices(&self) -> impl Iterator<Item = Self::Vertex> {
         (0..self.vertices.len()).map(Vertex)
     }
 
-    fn neighbors(&self, v: Self::Vertex) -> impl Iterator<Item = Self::Vertex> {
+    fn adjacent_vertices(&self, v: Self::Vertex) -> impl Iterator<Item = Self::Vertex> {
-        VertexNeighborIterator {
+        VertexAdjacenceIterator {
             graph: self,
             incidence: self.vertices[v.0].first_incidence,
         }

src/models/graph.rs

@@ -20,15 +20,15 @@ pub struct VertexIncidenceHeader {
 
 pub struct IncidenceEntry {
     next: Option<IncidenceSlot>,
-    neighbor: VertexSlot,
+    adjacent: VertexSlot,
 }
 
-struct VertexNeighborIterator<'a> {
+struct VertexAdjacenceIterator<'a> {
     graph: &'a Graph,
     incidence: Option<IncidenceSlot>,
 }
 
-impl<'a> Iterator for VertexNeighborIterator<'a> {
+impl<'a> Iterator for VertexAdjacenceIterator<'a> {
     type Item = Vertex;
 
     fn next(&mut self) -> Option<Self::Item> {
@@ -37,7 +37,7 @@ impl<'a> Iterator for VertexNeighborIterator<'a> {
         let index = self.graph.incidences.get_idx(incidence.0)?;
         let entry = &self.graph.incidences[index];
         self.incidence = entry.next;
-        self.graph.vertices.get_idx(entry.neighbor.0)
+        self.graph.vertices.get_idx(entry.adjacent.0)
     }
 }
 
@@ -89,7 +89,7 @@ impl Graph {
     fn add_incidence(&mut self, v1: Vertex, v2: Vertex) -> Edge {
         let edge = self.incidences.insert(IncidenceEntry {
             next: self.vertices[v1].first_incidence.take(),
-            neighbor: VertexSlot(v2.arr_idx()),
+            adjacent: VertexSlot(v2.arr_idx()),
         });
         self.vertices[v1].incidence_count += 1;
         self.vertices[v1].first_incidence = Some(IncidenceSlot(edge.arr_idx()));
@@ -124,12 +124,12 @@ impl Graph {
         let source_vertex = self
             .vertices
             .get_idx(source.0)
-            .expect("missing incident neighbor, corrupt internal data state");
+            .expect("missing incident vertex, corrupt internal data state");
         let vertex_header = &mut self.vertices[source_vertex];
         vertex_header.incidence_count -= if is_loop { 2 } else { 1 };
         let first = vertex_header
             .first_incidence
-            .expect("incident neighbor without incidences, corrupt internal data state");
+            .expect("incident vertex without incidences, corrupt internal data state");
         if first.0 == e.arr_idx() {
             vertex_header.first_incidence = next;
         } else {
@@ -184,15 +184,15 @@ impl GraphTopology for Graph {
     }
 
     fn are_adjacent(&self, v1: Self::Vertex, v2: Self::Vertex) -> bool {
-        self.neighbors(v1).any(|x| x == v2)
+        self.adjacent_vertices(v1).any(|x| x == v2)
     }
 
     fn vertices(&self) -> impl Iterator<Item = Self::Vertex> {
         self.vertices.iter().map(|(i, _)| i)
     }
 
-    fn neighbors(&self, v: Self::Vertex) -> impl Iterator<Item = Self::Vertex> {
+    fn adjacent_vertices(&self, v: Self::Vertex) -> impl Iterator<Item = Self::Vertex> {
-        VertexNeighborIterator {
+        VertexAdjacenceIterator {
             graph: self,
             incidence: self.vertices[v].first_incidence,
         }
@@ -233,8 +233,8 @@ impl GraphTopologyDeletion for Graph {
             // Since v is being deleted, there are no update_incidence_list() calls for e, no need
             // to fix v's incidence list.
             let (f, e_entry, f_entry) = self.remove_incidence_pair(e);
-            if e_entry.neighbor != f_entry.neighbor {
+            if e_entry.adjacent != f_entry.adjacent {
-                self.update_incidence_list(f, e_entry.neighbor, f_entry.next, false);
+                self.update_incidence_list(f, e_entry.adjacent, f_entry.next, false);
             } else {
                 cursor.incidence = f_entry.next;
             }
@@ -246,13 +246,13 @@ impl GraphTopologyDeletion for Graph {
     // the predecessor, never the removed entries themselves.
     fn delete_edge(&mut self, e: Self::Edge) {
         let (f, e_entry, f_entry) = self.remove_incidence_pair(e);
-        if e_entry.neighbor != f_entry.neighbor {
+        if e_entry.adjacent != f_entry.adjacent {
-            self.update_incidence_list(e, f_entry.neighbor, e_entry.next, false);
+            self.update_incidence_list(e, f_entry.adjacent, e_entry.next, false);
-            self.update_incidence_list(f, e_entry.neighbor, f_entry.next, false);
+            self.update_incidence_list(f, e_entry.adjacent, f_entry.next, false);
         } else if f_entry.next.is_some_and(|i| e.arr_idx() == i.0) {
-            self.update_incidence_list(f, e_entry.neighbor, e_entry.next, true);
+            self.update_incidence_list(f, e_entry.adjacent, e_entry.next, true);
         } else {
-            self.update_incidence_list(e, e_entry.neighbor, f_entry.next, true);
+            self.update_incidence_list(e, e_entry.adjacent, f_entry.next, true);
         }
     }
 }

src/testing/graph_topology_testing.rs

@@ -192,26 +192,26 @@ macro_rules! graph_topology_tests {
         }
 
         #[test]
-        fn neighbors_empty() {
+        fn adjacent_vertices_empty() {
             let mut graph = <$T>::new();
             let vertex = graph.add_vertex();
             assert_eq!(
-                graph.neighbors(vertex).count(),
+                graph.adjacent_vertices(vertex).count(),
                 0,
-                "neighbor iterator of vertex with degree 0 should have no elements"
+                "adjacent vertex iterator of vertex with degree 0 should have no elements"
             );
         }
 
         #[test]
-        fn neighbors() {
+        fn adjacent_vertices() {
             let (graph, vertices, _) = make_test_graph();
-            // Checks neighbors of vertex 4.
+            // Checks adjacency of vertex 4.
             assert_eq!(
-                graph.neighbors(vertices[4]).count(),
+                graph.adjacent_vertices(vertices[4]).count(),
                 7,
-                "unexpected neighbor count"
+                "unexpected adjacency count"
             );
-            let mut expected_neighbors = vec![
+            let mut expected_adjacency = vec![
                 vertices[1],
                 vertices[2],
                 vertices[2],
@@ -220,21 +220,21 @@ macro_rules! graph_topology_tests {
                 vertices[7],
                 vertices[8],
             ];
-            for v in graph.neighbors(vertices[4]) {
+            for v in graph.adjacent_vertices(vertices[4]) {
-                let i = expected_neighbors
+                let i = expected_adjacency
                     .iter()
                     .position(|w| *w == v)
                     .expect(&format!(
-                        "unexpected neighbor {v:?} of {:?} from the iterator",
+                        "unexpected adjacent vertex {v:?} of {:?} from the iterator",
                         vertices[4]
                     ));
-                expected_neighbors.swap_remove(i);
+                expected_adjacency.swap_remove(i);
             }
             assert_eq!(
-                expected_neighbors.len(),
+                expected_adjacency.len(),
                 0,
-                "expected neighbors {:?} of {:?} were not matched by the iterator",
+                "expected adjacent vertices {:?} of {:?} were not matched by the iterator",
-                expected_neighbors,
+                expected_adjacency,
                 vertices[4]
             );
         }
@@ -276,18 +276,18 @@ macro_rules! graph_topology_tests {
                 graph.are_adjacent(v, v),
                 "vertex with loop edge should be adjacent to itself"
             );
-            let mut neighbors = graph.neighbors(v);
+            let mut iter = graph.adjacent_vertices(v);
+            assert_eq!(iter.next(), Some(v), "vertex should be adjacent to itself");
             assert_eq!(
-                neighbors.next(),
+                iter.next(),
                 Some(v),
-                "vertex should be neighbor of itself"
+                "vertex should be adjacent to itself twice"
             );
             assert_eq!(
-                neighbors.next(),
+                iter.next(),
-                Some(v),
+                None,
-                "vertex should be neighbor of itself twice"
+                "too many adjacent vertices from iterator"
             );
-            assert_eq!(neighbors.next(), None, "too many neighbors from iterator");
         }
 
         #[test]
@@ -312,20 +312,20 @@ macro_rules! graph_topology_tests {
                 "should be adjacent"
             );
             for i in 0..2 {
-                let mut neighbors = graph.neighbors(vertices[i]);
+                let mut iter = graph.adjacent_vertices(vertices[i]);
                 for j in 0..k {
                     assert_eq!(
-                        neighbors.next(),
+                        iter.next(),
                         Some(vertices[1 - i]),
-                        "neighbor {j} of vertex {:?} should be {:?}",
+                        "adjacent vertex {j} of vertex {:?} should be {:?}",
                         vertices[i],
                         vertices[1 - i]
                     );
                 }
                 assert_eq!(
-                    neighbors.next(),
+                    iter.next(),
                     None,
-                    "too many neighbors of {:?} from iterator",
+                    "too many adjacent vertices of {:?} from iterator",
                     vertices[i]
                 );
             }
@@ -439,7 +439,7 @@ macro_rules! graph_topology_deletion_tests {
             }
             for v in [vertices[1], vertices[4], vertices[5], vertices[6]] {
                 assert!(
-                    !graph.neighbors(v).any(|u| u == vertices[2]),
+                    !graph.adjacent_vertices(v).any(|u| u == vertices[2]),
                     "unexpected adjacency of {v:?} to deleted vertex {:?}",
                     vertices[2]
                 );

src/traits.rs

@@ -17,7 +17,7 @@ pub trait GraphTopology {
     fn degree(&self, v: Self::Vertex) -> usize;
     fn are_adjacent(&self, v1: Self::Vertex, v2: Self::Vertex) -> bool;
     fn vertices(&self) -> impl Iterator<Item = Self::Vertex>;
-    fn neighbors(&self, v: Self::Vertex) -> impl Iterator<Item = Self::Vertex>;
+    fn adjacent_vertices(&self, v: Self::Vertex) -> impl Iterator<Item = Self::Vertex>;
     fn edges(&self) -> impl Iterator<Item = Self::Edge>;
     fn add_vertex(&mut self) -> Self::Vertex;
     fn add_edge(&mut self, v1: Self::Vertex, v2: Self::Vertex) -> Self::Edge;