apply code improvements suggested by intelliJ

src/main/java/core/ListDiscreteActionSpace.java

@@ -1,7 +1,10 @@
 package core;
 
 import java.io.Serializable;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
 
 /**
  * Implementation of a discrete action space.
@@ -18,6 +21,7 @@ public class ListDiscreteActionSpace<A extends Enum> implements DiscreteActionSp
         actions = new ArrayList<>();
     }
 
+    @SafeVarargs
     public ListDiscreteActionSpace(A... actions){
         this.actions = new ArrayList<>(Arrays.asList(actions));
     }

src/main/java/core/algo/mc/MonteCarloControlEGreedy.java

@@ -21,7 +21,7 @@ public class MonteCarloControlEGreedy<A extends Enum> extends EpisodicLearning<A
 
     private Map<Pair<State, A>, Double> returnSum;
     private Map<Pair<State, A>, Integer> returnCount;
-    private boolean isEveryVisit;
+    private final boolean isEveryVisit;
 
 
     public MonteCarloControlEGreedy(Environment<A> environment, DiscreteActionSpace<A> actionSpace, float discountFactor, float epsilon, int delay, boolean useEveryVisit) {

src/main/java/core/algo/td/QLearningOffPolicyTDControl.java

@@ -34,7 +34,7 @@ public class QLearningOffPolicyTDControl<A extends Enum> extends EpisodicLearnin
         }
 
         StepResultEnvironment envResult = null;
-        Map<A, Double> actionValues = null;
+        Map<A, Double> actionValues;
 
         sumOfRewards = 0;
         while(envResult == null || !envResult.isDone()) {

src/main/java/core/controller/RLController.java

@@ -39,6 +39,7 @@ public class RLController<A extends Enum> implements LearningListener {
     protected int prevDelay;
     protected volatile boolean printNextEpisode;
 
+    @SafeVarargs
     public RLController(Environment<A> env, Method method, A... actions) {
         setEnvironment(env);
         setMethod(method);
@@ -102,9 +103,7 @@ public class RLController<A extends Enum> implements LearningListener {
             if(learning.isCurrentlyLearning()){
                 ((EpisodicLearning<A>) learning).learnMoreEpisodes(nrOfEpisodes);
             }else{
-                new Thread(() -> {
-                    ((EpisodicLearning<A>) learning).learn(nrOfEpisodes);
-                }).start();
+                new Thread(() -> ((EpisodicLearning<A>) learning).learn(nrOfEpisodes)).start();
             }
         } else {
             throw new RuntimeException("Triggering onLearnMoreEpisodes on non-episodic learning!");
@@ -179,7 +178,7 @@ public class RLController<A extends Enum> implements LearningListener {
     public void onEpisodeEnd(List<Double> rewardHistory) {
         latestRewardsHistory = rewardHistory;
         if(printNextEpisode) {
-            System.out.println("Episode " + ((EpisodicLearning<A>) learning).getCurrentEpisode() + " Latest Reward: " + rewardHistory.get(rewardHistory.size() - 1));
+            System.out.println("Episode " + learning.getCurrentEpisode() + " Latest Reward: " + rewardHistory.get(rewardHistory.size() - 1));
             System.out.println("Eps/sec: " + ((EpisodicLearning<A>) learning).getEpisodePerSecond());
             printNextEpisode = false;
         }

src/main/java/core/controller/RLControllerGUI.java

@@ -13,6 +13,7 @@ import java.util.List;
 public class RLControllerGUI<A extends Enum> extends RLController<A> implements ViewListener {
     private LearningView learningView;
 
+    @SafeVarargs
     public RLControllerGUI(Environment<A> env, Method method, A... actions) {
         super(env, method, actions);
     }
@@ -102,7 +103,7 @@ public class RLControllerGUI<A extends Enum> extends RLController<A> implements
     @Override
     public void onLearningEnd() {
         super.onLearningEnd();
-        onSaveState(method.toString() + System.currentTimeMillis() / 1000 + (learning instanceof EpisodicLearning ? "e" + ((EpisodicLearning) learning).getCurrentEpisode() : ""));
+        onSaveState(method.toString() + System.currentTimeMillis() / 1000 + (learning instanceof EpisodicLearning ? "e" + learning.getCurrentEpisode() : ""));
         SwingUtilities.invokeLater(() -> learningView.updateRewardGraph(latestRewardsHistory));
     }
 }

src/main/java/core/gui/LearningInfoPanel.java

@@ -85,9 +85,7 @@ public class LearningInfoPanel extends JPanel {
             add(learnMoreEpisodesButton);
         }
         showQTableButton = new JButton("Show Q-Table");
-        showQTableButton.addActionListener(e -> {
-            viewListener.onShowQTable();
-        });
+        showQTableButton.addActionListener(e -> viewListener.onShowQTable());
         add(drawEnvironmentCheckbox);
         add(smoothGraphCheckbox);
         add(last100Checkbox);