refactor: rename edge class to Edge (Java naming convention)

Gvisual/src/gvisual/AdjacencyMatrixHeatmap.java

@@ -26,9 +26,9 @@
  */
 public class AdjacencyMatrixHeatmap extends JPanel {
 
-    private final Graph<String, edge> graph;
+    private final Graph<String, Edge> graph;
     private List<String> nodeOrder;
-    private final Map<String, Map<String, edge>> adjacency;
+    private final Map<String, Map<String, Edge>> adjacency;
     private int cellSize = 12;
     private int offsetX = 0;
     private int offsetY = 0;
@@ -49,7 +49,7 @@ public class AdjacencyMatrixHeatmap extends JPanel {
     private static final Color HIGHLIGHT_COLOR = new Color(255, 255, 255, 40);
     private static final Color LABEL_COLOR = new Color(200, 200, 200);
 
-    public AdjacencyMatrixHeatmap(Graph<String, edge> graph) {
+    public AdjacencyMatrixHeatmap(Graph<String, Edge> graph) {
         this.graph = graph;
         this.adjacency = new HashMap<>();
         setBackground(BG_COLOR);
@@ -62,7 +62,7 @@ public AdjacencyMatrixHeatmap(Graph<String, edge> graph) {
 
     private void buildAdjacency() {
         adjacency.clear();
-        for (edge e : graph.getEdges()) {
+        for (Edge e : graph.getEdges()) {
             String v1 = e.getVertex1();
             String v2 = e.getVertex2();
             adjacency.computeIfAbsent(v1, k -> new HashMap<>()).put(v2, e);
@@ -192,7 +192,7 @@ public String getToolTipText(MouseEvent e) {
             if (hoveredRow.equals(hoveredCol)) {
                 return "Node: " + hoveredRow + " (degree: " + graph.degree(hoveredRow) + ")";
             }
-            Map<String, edge> rowMap = adjacency.get(hoveredRow);
+            Map<String, Edge> rowMap = adjacency.get(hoveredRow);
             if (rowMap != null && rowMap.containsKey(hoveredCol)) {
                 edge ed = rowMap.get(hoveredCol);
                 String type = getEdgeTypeName(ed.getType());
@@ -216,7 +216,7 @@ private String getEdgeTypeName(String type) {
         }
     }
 
-    private Color getEdgeColor(edge e) {
+    private Color getEdgeColor(Edge e) {
         if (e == null) return DEFAULT_COLOR;
         String type = e.getType();
         if (type == null) return DEFAULT_COLOR;
@@ -269,7 +269,7 @@ protected void paintComponent(Graphics g2) {
                     int brightness = Math.min(255, 40 + deg * 15);
                     g.setColor(new Color(brightness, brightness, brightness));
                 } else {
-                    Map<String, edge> rowMap = adjacency.get(nodeR);
+                    Map<String, Edge> rowMap = adjacency.get(nodeR);
                     if (rowMap != null && rowMap.containsKey(nodeC)) {
                         edge e = rowMap.get(nodeC);
                         Color base = getEdgeColor(e);
@@ -347,7 +347,7 @@ protected void paintComponent(Graphics g2) {
         };
         for (int i = 0; i < legend.length; i++) {
             int ly = legendY + 20 + i * 22;
-            edge dummy = new edge(legend[i][1], "", "");
+            edge dummy = new Edge(legend[i][1], "", "");
             g.setColor(getEdgeColor(dummy));
             g.fillRect(legendX, ly - 10, 14, 14);
             g.setColor(LABEL_COLOR);
@@ -366,7 +366,7 @@ protected void paintComponent(Graphics g2) {
     /**
      * Creates a dialog window containing the heatmap with controls.
      */
-    public static JDialog createDialog(JFrame parent, Graph<String, edge> graph) {
+    public static JDialog createDialog(JFrame parent, Graph<String, Edge> graph) {
         JDialog dialog = new JDialog(parent, "Adjacency Matrix Heatmap", false);
         dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
 

Gvisual/src/gvisual/ArticulationPanelController.java

@@ -22,18 +22,18 @@ public class ArticulationPanelController {
     private final JButton analyzeButton;
     private final JButton clearButton;
 
-    private final Supplier<Graph<String, edge>> graphSupplier;
+    private final Supplier<Graph<String, Edge>> graphSupplier;
     private final Runnable onOverlayChanged;
 
     private boolean overlayActive;
     private final Set<String> articulationPoints = new HashSet<>();
-    private final Set<edge> bridgeEdges = new HashSet<>();
+    private final Set<Edge> bridgeEdges = new HashSet<>();
 
     /**
      * @param graphSupplier     supplies the current graph
      * @param onOverlayChanged  callback to refresh renderers/visualization after overlay changes
      */
-    public ArticulationPanelController(Supplier<Graph<String, edge>> graphSupplier,
+    public ArticulationPanelController(Supplier<Graph<String, Edge>> graphSupplier,
                                         Runnable onOverlayChanged) {
         this.graphSupplier = graphSupplier;
         this.onOverlayChanged = onOverlayChanged;
@@ -78,10 +78,10 @@ public ArticulationPanelController(Supplier<Graph<String, edge>> graphSupplier,
     public JPanel getPanel() { return panel; }
     public boolean isOverlayActive() { return overlayActive; }
     public Set<String> getArticulationPoints() { return Collections.unmodifiableSet(articulationPoints); }
-    public Set<edge> getBridgeEdges() { return Collections.unmodifiableSet(bridgeEdges); }
+    public Set<Edge> getBridgeEdges() { return Collections.unmodifiableSet(bridgeEdges); }
 
     private void runAnalysis() {
-        Graph<String, edge> g = graphSupplier.get();
+        Graph<String, Edge> g = graphSupplier.get();
         if (g == null || g.getVertexCount() == 0) {
             summaryLabel.setText("<html>No graph loaded.</html>");
             return;

Gvisual/src/gvisual/ArticulationPointAnalyzer.java

@@ -25,15 +25,15 @@
  */
 public class ArticulationPointAnalyzer {
 
-    private final Graph<String, edge> graph;
+    private final Graph<String, Edge> graph;
 
     /**
      * Create a new analyzer for the given graph.
      *
      * @param graph the JUNG graph to analyze (must not be null)
      * @throws IllegalArgumentException if graph is null
      */
-    public ArticulationPointAnalyzer(Graph<String, edge> graph) {
+    public ArticulationPointAnalyzer(Graph<String, Edge> graph) {
         if (graph == null) {
             throw new IllegalArgumentException("Graph must not be null");
         }
@@ -52,7 +52,7 @@ public static class Bridge {
         private final int componentSizeA;
         private final int componentSizeB;
 
-        public Bridge(edge bridgeEdge, String endpoint1, String endpoint2,
+        public Bridge(Edge bridgeEdge, String endpoint1, String endpoint2,
                       int componentSizeA, int componentSizeB) {
             this.bridgeEdge = bridgeEdge;
             this.endpoint1 = endpoint1;
@@ -227,7 +227,7 @@ public AnalysisResult analyze() {
         Map<String, String> parent = new HashMap<String, String>();
         Set<String> visited = new HashSet<String>();
         Set<String> articulationPoints = new LinkedHashSet<String>();
-        List<edge> bridgeEdges = new ArrayList<edge>();
+        List<Edge> bridgeEdges = new ArrayList<Edge>();
         int[] timer = {0};
 
         // Run DFS from each unvisited vertex (handles disconnected graphs)
@@ -245,7 +245,7 @@ public AnalysisResult analyze() {
         for (String ap : articulationPoints) {
             int degree = graph.degree(ap);
             Map<String, Integer> edgeTypeCounts = new HashMap<String, Integer>();
-            for (edge e : graph.getIncidentEdges(ap)) {
+            for (Edge e : graph.getIncidentEdges(ap)) {
                 String type = e.getType() != null ? e.getType() : "unknown";
                 edgeTypeCounts.put(type, edgeTypeCounts.getOrDefault(type, 0) + 1);
             }
@@ -260,7 +260,7 @@ public AnalysisResult analyze() {
 
         // Build bridge details with component size estimation
         List<Bridge> bridges = new ArrayList<Bridge>();
-        for (edge e : bridgeEdges) {
+        for (Edge e : bridgeEdges) {
             String v1 = e.getVertex1() != null ? e.getVertex1() : findEndpoints(e)[0];
             String v2 = e.getVertex2() != null ? e.getVertex2() : findEndpoints(e)[1];
             int[] sizes = estimateComponentSizes(v1, v2, e);
@@ -284,7 +284,7 @@ private void dfs(String u,
                      Map<String, String> parent,
                      Set<String> visited,
                      Set<String> articulationPoints,
-                     List<edge> bridges,
+                     List<Edge> bridges,
                      int[] timer) {
         visited.add(u);
         disc.put(u, timer[0]);
@@ -330,7 +330,7 @@ private void dfs(String u,
      * Find the edge connecting two vertices.
      */
     private edge findEdge(String u, String v) {
-        for (edge e : graph.getIncidentEdges(u)) {
+        for (Edge e : graph.getIncidentEdges(u)) {
             String v1 = e.getVertex1();
             String v2 = e.getVertex2();
             // Also check via JUNG endpoints since vertex1/vertex2 may be null
@@ -348,7 +348,7 @@ private edge findEdge(String u, String v) {
     /**
      * Find endpoints of an edge via the graph when vertex1/vertex2 may be null.
      */
-    private String[] findEndpoints(edge e) {
+    private String[] findEndpoints(Edge e) {
         Collection<String> endpoints = graph.getEndpoints(e);
         if (endpoints != null && endpoints.size() == 2) {
             Iterator<String> it = endpoints.iterator();
@@ -414,7 +414,7 @@ private Set<String> bfsExcludingEdge(String start, edge excluded) {
 
         while (!queue.isEmpty()) {
             String current = queue.poll();
-            for (edge e : graph.getIncidentEdges(current)) {
+            for (Edge e : graph.getIncidentEdges(current)) {
                 if (e == excluded) continue;
                 Collection<String> endpoints = graph.getEndpoints(e);
                 for (String neighbor : endpoints) {

Gvisual/src/gvisual/BipartiteAnalyzer.java

@@ -33,7 +33,7 @@ public class BipartiteAnalyzer {
     private static final String NIL = "__NIL__";
     private static final int INF = Integer.MAX_VALUE;
 
-    private final Graph<String, edge> graph;
+    private final Graph<String, Edge> graph;
     private Map<String, Integer> coloring;
     private boolean bipartite;
     private boolean computed;
@@ -45,7 +45,7 @@ public class BipartiteAnalyzer {
      * @param graph the JUNG graph to analyze
      * @throws IllegalArgumentException if graph is null
      */
-    public BipartiteAnalyzer(Graph<String, edge> graph) {
+    public BipartiteAnalyzer(Graph<String, Edge> graph) {
         if (graph == null) {
             throw new IllegalArgumentException("Graph must not be null");
         }

Gvisual/src/gvisual/CentralityPanelController.java

@@ -24,12 +24,12 @@ public class CentralityPanelController {
     private final JButton computeButton;
     private final JButton clearButton;
 
-    private final Supplier<Graph<String, edge>> graphSupplier;
+    private final Supplier<Graph<String, Edge>> graphSupplier;
 
     private boolean active;
     private final Map<String, NodeCentralityAnalyzer.CentralityResult> results = new HashMap<>();
 
-    public CentralityPanelController(Supplier<Graph<String, edge>> graphSupplier) {
+    public CentralityPanelController(Supplier<Graph<String, Edge>> graphSupplier) {
         this.graphSupplier = graphSupplier;
 
         Font labelFont = new Font("SansSerif", Font.PLAIN, 12);
@@ -106,7 +106,7 @@ public Map<String, NodeCentralityAnalyzer.CentralityResult> getResults() {
     }
 
     private void runAnalysis() {
-        Graph<String, edge> g = graphSupplier.get();
+        Graph<String, Edge> g = graphSupplier.get();
         if (g == null || g.getVertexCount() == 0) {
             summaryLabel.setText("<html>No graph loaded.</html>");
             return;

Gvisual/src/gvisual/CentralityRadarExporter.java

@@ -33,10 +33,10 @@
  */
 public class CentralityRadarExporter {
 
-    private final Graph<String, edge> graph;
+    private final Graph<String, Edge> graph;
     private String title = "Centrality Radar Chart";
 
-    public CentralityRadarExporter(Graph<String, edge> graph) {
+    public CentralityRadarExporter(Graph<String, Edge> graph) {
         if (graph == null) throw new IllegalArgumentException("Graph must not be null");
         this.graph = graph;
     }

Gvisual/src/gvisual/ChordalGraphAnalyzer.java

@@ -192,7 +192,7 @@ public String toTextReport() {
      * @param graph the graph
      * @return MCS ordering (last eliminated first)
      */
-    public static List<String> maximumCardinalitySearch(Graph<String, edge> graph) {
+    public static List<String> maximumCardinalitySearch(Graph<String, Edge> graph) {
         if (graph == null) return Collections.emptyList();
         Collection<String> vertices = graph.getVertices();
         if (vertices == null || vertices.isEmpty()) return Collections.emptyList();
@@ -247,7 +247,7 @@ public static List<String> maximumCardinalitySearch(Graph<String, edge> graph) {
      * @param graph the graph
      * @return ChordalityResult with PEO if chordal, or a chordless cycle if not
      */
-    public static ChordalityResult testChordality(Graph<String, edge> graph) {
+    public static ChordalityResult testChordality(Graph<String, Edge> graph) {
         if (graph == null || graph.getVertexCount() == 0) {
             return new ChordalityResult(true, Collections.<String>emptyList(), null);
         }
@@ -349,7 +349,7 @@ private static List<String> findChordlessCycle(Map<String, Set<String>> adj,
      * @param graph the graph
      * @return coloring result
      */
-    public static ColoringResult optimalColoring(Graph<String, edge> graph) {
+    public static ColoringResult optimalColoring(Graph<String, Edge> graph) {
         if (graph == null || graph.getVertexCount() == 0) {
             return new ColoringResult(Collections.<String, Integer>emptyMap(), 0);
         }
@@ -396,7 +396,7 @@ public static ColoringResult optimalColoring(Graph<String, edge> graph) {
      * @param graph the graph
      * @return vertices of a maximum clique
      */
-    public static Set<String> maximumClique(Graph<String, edge> graph) {
+    public static Set<String> maximumClique(Graph<String, Edge> graph) {
         if (graph == null || graph.getVertexCount() == 0) {
             return Collections.emptySet();
         }
@@ -433,7 +433,7 @@ public static Set<String> maximumClique(Graph<String, edge> graph) {
         return best;
     }
 
-    private static Set<String> findMaxCliqueGreedy(Graph<String, edge> graph) {
+    private static Set<String> findMaxCliqueGreedy(Graph<String, Edge> graph) {
         Map<String, Set<String>> adj = GraphUtils.buildAdjacencyMap(graph);
         // Sort vertices by degree descending
         List<String> sorted = new ArrayList<>(graph.getVertices());
@@ -467,7 +467,7 @@ private static Set<String> findMaxCliqueGreedy(Graph<String, edge> graph) {
      * @param graph the graph
      * @return list of maximal cliques
      */
-    public static List<Set<String>> allMaximalCliques(Graph<String, edge> graph) {
+    public static List<Set<String>> allMaximalCliques(Graph<String, Edge> graph) {
         if (graph == null || graph.getVertexCount() == 0) {
             return Collections.emptyList();
         }
@@ -528,7 +528,7 @@ public static List<Set<String>> allMaximalCliques(Graph<String, edge> graph) {
      * @param graph the graph
      * @return list of clique tree nodes with neighbor relationships
      */
-    public static List<CliqueTreeNode> buildCliqueTree(Graph<String, edge> graph) {
+    public static List<CliqueTreeNode> buildCliqueTree(Graph<String, Edge> graph) {
         List<Set<String>> cliques = allMaximalCliques(graph);
         if (cliques.isEmpty()) return Collections.emptyList();
 
@@ -597,7 +597,7 @@ private static int intersectionSize(Set<String> a, Set<String> b) {
      * @param graph the graph
      * @return fill-in result with list of edges to add
      */
-    public static FillInResult computeFillIn(Graph<String, edge> graph) {
+    public static FillInResult computeFillIn(Graph<String, Edge> graph) {
         if (graph == null || graph.getVertexCount() == 0) {
             return new FillInResult(Collections.<String[]>emptyList());
         }
@@ -656,7 +656,7 @@ public static FillInResult computeFillIn(Graph<String, edge> graph) {
      * @param graph the graph
      * @return list of minimal separators
      */
-    public static List<Set<String>> minimalSeparators(Graph<String, edge> graph) {
+    public static List<Set<String>> minimalSeparators(Graph<String, Edge> graph) {
         List<Set<String>> cliques = allMaximalCliques(graph);
         List<CliqueTreeNode> tree = buildCliqueTree(graph);
         if (tree.size() <= 1) return Collections.emptyList();
@@ -684,7 +684,7 @@ public static List<Set<String>> minimalSeparators(Graph<String, edge> graph) {
      * @param graph the graph
      * @return treewidth, or -1 for empty graph
      */
-    public static int treewidth(Graph<String, edge> graph) {
+    public static int treewidth(Graph<String, Edge> graph) {
         Set<String> mc = maximumClique(graph);
         return mc.isEmpty() ? -1 : mc.size() - 1;
     }
@@ -698,7 +698,7 @@ public static int treewidth(Graph<String, edge> graph) {
      * @param order elimination order
      * @return list of cliques formed at each elimination step
      */
-    public static List<Set<String>> eliminationCliques(Graph<String, edge> graph,
+    public static List<Set<String>> eliminationCliques(Graph<String, Edge> graph,
                                                         List<String> order) {
         if (graph == null || order == null) return Collections.emptyList();
 
@@ -745,7 +745,7 @@ public static List<Set<String>> eliminationCliques(Graph<String, edge> graph,
      * @param graph the graph
      * @return full analysis report
      */
-    public static ChordalReport analyze(Graph<String, edge> graph) {
+    public static ChordalReport analyze(Graph<String, Edge> graph) {
         int vc = graph != null ? graph.getVertexCount() : 0;
         int ec = graph != null ? graph.getEdgeCount() : 0;