Minor Cleanup.

Author: RuedigerLunde

aima-core/src/main/java/aima/core/environment/map/MapAgent.java

@@ -31,7 +31,7 @@ public class MapAgent extends ProblemSolvingAgent<DynamicPercept, String, MoveTo
     protected final List<String> goals = new ArrayList<>();
     protected int nextGoalPos = 0;
 
-    private SearchForActions<String, MoveToAction> search;
+    private final SearchForActions<String, MoveToAction> search;
     private Function<String, ToDoubleFunction<Node<String, MoveToAction>>> hFnFactory;
     protected Notifier notifier;
 

aima-core/src/main/java/aima/core/search/adversarial/MonteCarloTreeSearch.java

@@ -42,8 +42,8 @@
 
 public class MonteCarloTreeSearch<S, A, P> implements AdversarialSearch<S, A> {
 	private int iterations = 0;
-	private Game<S, A, P> game;
-	private GameTree<S, A> tree;
+	private final Game<S, A, P> game;
+	private final GameTree<S, A> tree;
 
 	public MonteCarloTreeSearch(Game<S, A, P> game, int iterations) {
 		this.game = game;
@@ -73,7 +73,7 @@ public A makeDecision(S state) {
 		return bestAction(tree.getRoot());
 	}
 
-	private Node<S, A> select(GameTree gameTree) {
+	private Node<S, A> select(GameTree<S, A> gameTree) {
 		Node<S, A> node = gameTree.getRoot();
 		while (!game.isTerminal(node.getState()) && isNodeFullyExpanded(node)) {
 			node = gameTree.getChildWithMaxUCT(node);
@@ -82,23 +82,21 @@ private Node<S, A> select(GameTree gameTree) {
 	}
 
 	private Node<S, A> expand(Node<S, A> leaf) {
-		if (game.isTerminal(leaf.getState())) return leaf;
-		else {
-			Node<S, A> child = randomlySelectUnvisitedChild(leaf);
-			return child;
-		}
+		if (game.isTerminal(leaf.getState()))
+			return leaf;
+		else
+			return randomlySelectUnvisitedChild(leaf);
 	}
 
 	private boolean simulate(Node<S, A> node) {
 		while (!game.isTerminal(node.getState())) {
 			Random rand = new Random();
 			A a = game.getActions(node.getState()).get(rand.nextInt(game.getActions(node.getState()).size()));
 			S result = game.getResult(node.getState(), a);
-			NodeFactory nodeFactory = new NodeFactory();
+			NodeFactory<S, A> nodeFactory = new NodeFactory<>();
 			node = nodeFactory.createNode(result);
 		}
-		if (game.getUtility(node.getState(), game.getPlayer(tree.getRoot().getState())) > 0) return true;
-		else return false;
+		return game.getUtility(node.getState(), game.getPlayer(tree.getRoot().getState())) > 0;
 	}
 
 	private void backpropagate(boolean result, Node<S, A> node) {
@@ -135,8 +133,7 @@ private Node<S, A> randomlySelectUnvisitedChild(Node<S, A> node) {
 			if (!visitedChildren.contains(result)) unvisitedChildren.add(result);
 		}
 		Random rand = new Random();
-		Node<S, A> newChild = tree.addChild(node, unvisitedChildren.get(rand.nextInt(unvisitedChildren.size())));
-		return newChild;
+		return tree.addChild(node, unvisitedChildren.get(rand.nextInt(unvisitedChildren.size())));
 	}
 
 	@Override

aima-core/src/main/java/aima/core/util/datastructure/Pair.java

@@ -1,5 +1,7 @@
 package aima.core.util.datastructure;
 
+import java.util.Objects;
+
 /**
  * @author Ravi Mohan
  * @author Mike Stampone
@@ -44,22 +46,20 @@ public Y getSecond() {
 
 	@Override
 	public boolean equals(Object o) {
-		if (o instanceof Pair<?, ?>) {
+		if (o != null && getClass() == o.getClass()) {
 			Pair<?, ?> p = (Pair<?, ?>) o;
-			return (a == null ? p.a == null : a.equals(p.a)) &&
-					(b == null ? p.b == null : b.equals(p.b));
+			return Objects.equals(a, p.a) && Objects.equals(b, p.b);
 		}
 		return false;
 	}
 
 	@Override
 	public int hashCode() {
-		return (a == null ? 0 : a.hashCode()) + 31 * (b == null ? 0 : b.hashCode());
+		return (a == null ? 0 : 7 * a.hashCode()) + 31 * (b == null ? 0 : b.hashCode());
 	}
 
 	@Override
 	public String toString() {
-		return "< " + getFirst().toString() + " , " + getSecond().toString()
-				+ " > ";
+		return "< " + getFirst().toString() + " , " + getSecond().toString() + " > ";
 	}
 }

aimax-osm/src/main/java/aimax/osm/gui/fx/applications/ExtendedRouteFindingAgentOsmApp.java

@@ -23,6 +23,8 @@
 import java.util.function.Function;
 import java.util.function.ToDoubleFunction;
 
+// VM options (Java>8): --module-path ${PATH_TO_FX} --add-modules javafx.controls,javafx.fxml
+
 /**
  * Integrable application which demonstrates how different kinds of search
  * algorithms perform in a route finding scenario based on a real OSM map. This

aimax-osm/src/main/java/aimax/osm/gui/fx/applications/InteractiveMapViewerOsmApp.java

@@ -10,6 +10,8 @@
 
 import java.util.Locale;
 
+// VM options (Java>8): --module-path ${PATH_TO_FX} --add-modules javafx.controls,javafx.fxml
+
 /**
  * Shows a map of the city of Ulm with pan and zoom functionality (mouse drag, mouse wheel, arrow keys,
  * plus and minus keys). Set markers with Mouse-Left and remove them with Mouse-Right. Symbols can be changed in size

aimax-osm/src/main/java/aimax/osm/gui/fx/applications/OnlineAgentOsmApp.java

@@ -34,6 +34,8 @@
 import java.util.List;
 import java.util.function.ToDoubleFunction;
 
+// VM options (Java>8): --module-path ${PATH_TO_FX} --add-modules javafx.controls,javafx.fxml
+
 /**
  * Integrable application which demonstrates how the Learning Real-Time A*
  * (LRTA*) search agent performs compared to the Online DFS agent in a route

aimax-osm/src/main/java/aimax/osm/gui/fx/applications/RouteFindingAgentOsmApp.java

@@ -33,6 +33,8 @@
 import java.util.List;
 import java.util.function.ToDoubleFunction;
 
+// VM options (Java>8): --module-path ${PATH_TO_FX} --add-modules javafx.controls,javafx.fxml
+
 /**
  * Simple OSM route finding agent application which can be used as base class
  * for more advanced OSM agent applications. For example, by overriding some of

aimax-osm/src/main/java/aimax/osm/gui/fx/applications/RoutePlannerOsmApp.java

@@ -18,6 +18,8 @@
 import java.text.DecimalFormat;
 import java.util.List;
 
+// VM options (Java>8): --module-path ${PATH_TO_FX} --add-modules javafx.controls,javafx.fxml
+
 /**
  * Extendable application for route planning based on a real map of the city of Ulm.
  *

aimax-osm/src/main/java/aimax/osm/gui/fx/applications/SimpleMapViewerOsmApp.java

@@ -12,6 +12,8 @@
 
 import java.util.Locale;
 
+// VM options (Java>8): --module-path ${PATH_TO_FX} --add-modules javafx.controls,javafx.fxml
+
 /**
  * Simple demo application which shows a stage with the
  * map of Ulm, provided that a file with name ulm.osm is found