[O] Optimize code

src/main/java/mars/simulator/BackStepper.java

@@ -380,7 +380,7 @@ public class BackStepper
 
 
     // Represents a "back step" (undo action) on the stack.
-    private class BackStep
+    private static class BackStep
     {
         private int action;  // what do do MEMORY_RESTORE_WORD, etc
 
@@ -442,7 +442,7 @@ public class BackStepper
     // regardless of how many steps are executed.  This will speed things up a bit
     // and make life easier for the garbage collector.
 
-    private class BackstepStack
+    private static class BackstepStack
     {
         private final int capacity;
 

src/main/java/mars/simulator/ProgramArgumentList.java

@@ -49,7 +49,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 public class ProgramArgumentList
 {
 
-    ArrayList programArgumentList;
+    ArrayList<String> programArgumentList;
 
     /**
      * Constructor that parses string to produce list.  Delimiters are the default Java StringTokenizer delimiters
@@ -60,7 +60,7 @@ public class ProgramArgumentList
     public ProgramArgumentList(String args)
     {
         StringTokenizer st = new StringTokenizer(args);
-        programArgumentList = new ArrayList(st.countTokens());
+        programArgumentList = new ArrayList<>(st.countTokens());
         while (st.hasMoreTokens())
         {
             programArgumentList.add(st.nextToken());
@@ -86,7 +86,7 @@ public class ProgramArgumentList
      */
     public ProgramArgumentList(String[] list, int startPosition)
     {
-        programArgumentList = new ArrayList(list.length - startPosition);
+        programArgumentList = new ArrayList<>(list.length - startPosition);
         programArgumentList.addAll(Arrays.asList(list).subList(startPosition, list.length));
     }
 
@@ -95,7 +95,7 @@ public class ProgramArgumentList
      *
      * @param list ArrayList of String, each element containing one argument
      */
-    public ProgramArgumentList(ArrayList list)
+    public ProgramArgumentList(ArrayList<String> list)
     {
         this(list, 0);
     }
@@ -108,15 +108,15 @@ public class ProgramArgumentList
      * @param startPosition Index of array element containing the first argument; all remaining elements are assumed
      *     to contain an argument.
      */
-    public ProgramArgumentList(ArrayList list, int startPosition)
+    public ProgramArgumentList(ArrayList<? extends String> list, int startPosition)
     {
         if (list == null || list.size() < startPosition)
         {
-            programArgumentList = new ArrayList(0);
+            programArgumentList = new ArrayList<>(0);
         }
         else
         {
-            programArgumentList = new ArrayList(list.size() - startPosition);
+            programArgumentList = new ArrayList<>(list.size() - startPosition);
             for (int i = startPosition; i < list.size(); i++)
             {
                 programArgumentList.add(list.get(i));
@@ -166,10 +166,11 @@ public class ProgramArgumentList
         String programArgument;
         int[] argStartAddress = new int[programArgumentList.size()];
         try
-        { // needed for all memory writes
+        {
+            // needed for all memory writes
             for (int i = 0; i < programArgumentList.size(); i++)
             {
-                programArgument = (String) programArgumentList.get(i);
+                programArgument = programArgumentList.get(i);
                 Globals.memory.set(highAddress, 0, 1);  // trailing null byte for each argument
                 highAddress--;
                 for (int j = programArgument.length() - 1; j >= 0; j--)
@@ -206,9 +207,6 @@ public class ProgramArgumentList
             RegisterFile.getUserRegister("$sp").setValue(stackAddress + Memory.WORD_LENGTH_BYTES);
             RegisterFile.getUserRegister("$a0").setValue(argStartAddress.length); // argc
             RegisterFile.getUserRegister("$a1").setValue(stackAddress + Memory.WORD_LENGTH_BYTES + Memory.WORD_LENGTH_BYTES); // argv
-            //RegisterFile.updateRegister("$sp",stackAddress+Memory.WORD_LENGTH_BYTES);
-            //RegisterFile.updateRegister("$a0",argStartAddress.length); // argc
-            //RegisterFile.updateRegister("$a1",stackAddress+Memory.WORD_LENGTH_BYTES+Memory.WORD_LENGTH_BYTES); // argv
         }
         catch (AddressErrorException aee)
         {

src/main/java/mars/tools/AbstractMarsToolAndApplication.java

@@ -280,44 +280,27 @@ public abstract class AbstractMarsToolAndApplication extends JFrame implements M
         connectButton = new ConnectButton();
         connectButton.setToolTipText("Control whether tool will respond to running MIPS program");
         connectButton.addActionListener(
-            new ActionListener()
+            e ->
             {
-                public void actionPerformed(ActionEvent e)
+                if (connectButton.isConnected())
                 {
-                    if (connectButton.isConnected())
+                    connectButton.disconnect();
-                    {
+                }
-                        connectButton.disconnect();
+                else
-                    }
+                {
-                    else
+                    connectButton.connect();
-                    {
-                        connectButton.connect();
-                    }
                 }
             });
         connectButton.addKeyListener(new EnterKeyListener(connectButton));
 
         JButton resetButton = new JButton("Reset");
         resetButton.setToolTipText("Reset all counters and other structures");
-        resetButton.addActionListener(
+        resetButton.addActionListener(e -> reset());
-            new ActionListener()
-            {
-                public void actionPerformed(ActionEvent e)
-                {
-                    reset();
-                }
-            });
         resetButton.addKeyListener(new EnterKeyListener(resetButton));
 
         JButton closeButton = new JButton("Close");
         closeButton.setToolTipText("Close (exit) this tool");
-        closeButton.addActionListener(
+        closeButton.addActionListener(e -> performToolClosingDuties());
-            new ActionListener()
-            {
-                public void actionPerformed(ActionEvent e)
-                {
-                    performToolClosingDuties();
-                }
-            });
         closeButton.addKeyListener(new EnterKeyListener(closeButton));
 
         // Add all the buttons...
@@ -441,26 +424,12 @@ public abstract class AbstractMarsToolAndApplication extends JFrame implements M
 
         JButton resetButton = new JButton("Reset");
         resetButton.setToolTipText("Reset all counters and other structures");
-        resetButton.addActionListener(
+        resetButton.addActionListener(e -> reset());
-            new ActionListener()
-            {
-                public void actionPerformed(ActionEvent e)
-                {
-                    reset();
-                }
-            });
         resetButton.addKeyListener(new EnterKeyListener(resetButton));
 
         JButton closeButton = new JButton("Exit");
         closeButton.setToolTipText("Exit this application");
-        closeButton.addActionListener(
+        closeButton.addActionListener(e -> performAppClosingDuties());
-            new ActionListener()
-            {
-                public void actionPerformed(ActionEvent e)
-                {
-                    performAppClosingDuties();
-                }
-            });
         closeButton.addKeyListener(new EnterKeyListener(closeButton));
 
 
@@ -735,7 +704,7 @@ public abstract class AbstractMarsToolAndApplication extends JFrame implements M
     //  are attached to the button at the time of the call.  Otherwise,
     //  it will call actionPerformed for the first action listener in the
     //  button's list.
-    protected class EnterKeyListener extends KeyAdapter
+    protected static class EnterKeyListener extends KeyAdapter
     {
         AbstractButton myButton;
 

src/main/java/mars/tools/KeyboardAndDisplaySimulator.java

@@ -840,7 +840,7 @@ public class KeyboardAndDisplaySimulator extends AbstractMarsToolAndApplication
     // NOTE: last argument TRUE means update only the MMIO Control register; FALSE means update both Control and Data.
     private synchronized void updateMMIOControlAndData(int controlAddr, int controlValue, int dataAddr, int dataValue, boolean controlOnly)
     {
-        if (!this.isBeingUsedAsAMarsTool || (this.isBeingUsedAsAMarsTool && connectButton.isConnected()))
+        if (!this.isBeingUsedAsAMarsTool || connectButton.isConnected())
         {
             synchronized (Globals.memoryAndRegistersLock)
             {