diff --git a/build.gradle b/build.gradle
index d7cef78..53a1e75 100644
--- a/build.gradle
+++ b/build.gradle
@@ -36,6 +36,7 @@ task generateJavaSources() {
         def source = """
             package com.annimon.ownlang;
             class Gen {
+                private Gen() {}
                 public static final String BUILD_DATE = "${new Date().format('YYMMdd')}";
             }
             """
diff --git a/src/main/java/com/annimon/ownlang/Console.java b/src/main/java/com/annimon/ownlang/Console.java
index d9e5c4f..6bf4a3e 100644
--- a/src/main/java/com/annimon/ownlang/Console.java
+++ b/src/main/java/com/annimon/ownlang/Console.java
@@ -50,9 +50,9 @@ public class Console {
     public static void handleException(Thread thread, Throwable throwable) {
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         try(final PrintStream ps = new PrintStream(baos)) {
-            ps.printf("%s in %s\n", throwable.getMessage(), thread.getName());
+            ps.printf("%s in %s%n", throwable.getMessage(), thread.getName());
             for (CallStack.CallInfo call : CallStack.getCalls()) {
-                ps.printf("\tat %s\n", call);
+                ps.printf("\tat %s%n", call);
             }
             ps.println();
             throwable.printStackTrace(ps);
@@ -74,4 +74,6 @@ public class Console {
         }
         return new File(filepath);
     }
+
+
 }
diff --git a/src/main/java/com/annimon/ownlang/Main.java b/src/main/java/com/annimon/ownlang/Main.java
index 25cae18..d999834 100644
--- a/src/main/java/com/annimon/ownlang/Main.java
+++ b/src/main/java/com/annimon/ownlang/Main.java
@@ -33,25 +33,9 @@ public final class Main {
     public static void main(String[] args) throws IOException {
         if (args.length == 0) {
             try {
-                final Options options = new Options();
-                options.showAst = false;
-                options.showTokens = false;
-                options.showMeasurements = false;
-                options.lintMode = false;
-                options.optimizationLevel = 0;
-                run(SourceLoader.readSource("program.own"), options);
+                runDefault();
             } catch (IOException ioe) {
-                System.out.println("OwnLang version " + VERSION + "\n\n" +
-                        "Usage: ownlang [options]\n" +
-                        "  options:\n" +
-                        "      -f, --file [input]  Run program file. Required.\n" +
-                        "      -r, --repl          Enter to a REPL mode\n" +
-                        "      -l, --lint          Find bugs in code\n" +
-                        "      -o N, --optimize N  Perform optimization with N passes\n" +
-                        "      -b, --beautify      Beautify source code\n" +
-                        "      -a, --showast       Show AST of program\n" +
-                        "      -t, --showtokens    Show lexical tokens\n" +
-                        "      -m, --showtime      Show elapsed time of parsing and execution");
+                printUsage();
             }
             return;
         }
@@ -139,6 +123,30 @@ public final class Main {
         run(input, options);
     }
 
+    private static void runDefault() throws IOException {
+        final Options options = new Options();
+        options.showAst = false;
+        options.showTokens = false;
+        options.showMeasurements = false;
+        options.lintMode = false;
+        options.optimizationLevel = 0;
+        run(SourceLoader.readSource("program.own"), options);
+    }
+
+    private static void printUsage() {
+        System.out.println("OwnLang version " + VERSION + "\n\n" +
+                "Usage: ownlang [options]\n" +
+                "  options:\n" +
+                "      -f, --file [input]  Run program file. Required.\n" +
+                "      -r, --repl          Enter to a REPL mode\n" +
+                "      -l, --lint          Find bugs in code\n" +
+                "      -o N, --optimize N  Perform optimization with N passes\n" +
+                "      -b, --beautify      Beautify source code\n" +
+                "      -a, --showast       Show AST of program\n" +
+                "      -t, --showtokens    Show lexical tokens\n" +
+                "      -m, --showtime      Show elapsed time of parsing and execution");
+    }
+
     private static void createOwnLangArgs(String[] javaArgs, int index) {
         if (index >= javaArgs.length) return;
         ownlangArgs = new String[javaArgs.length - index];
@@ -152,7 +160,8 @@ public final class Main {
         final List<Token> tokens = Lexer.tokenize(input);
         measurement.stop("Tokenize time");
         if (options.showTokens) {
-            for (int i = 0; i < tokens.size(); i++) {
+            final int tokensCount = tokens.size();
+            for (int i = 0; i < tokensCount; i++) {
                 System.out.println(i + " " + tokens.get(i));
             }
         }
@@ -205,7 +214,7 @@ public final class Main {
         boolean lintMode;
         int optimizationLevel;
 
-        public Options() {
+        Options() {
             showTokens = false;
             showAst = false;
             showMeasurements = false;
@@ -213,8 +222,8 @@ public final class Main {
             optimizationLevel = 0;
         }
 
-        public void validate() {
-            if (lintMode == true) {
+        void validate() {
+            if (lintMode) {
                 showTokens = false;
                 showAst = false;
                 showMeasurements = false;
diff --git a/src/main/java/com/annimon/ownlang/lib/Arguments.java b/src/main/java/com/annimon/ownlang/lib/Arguments.java
index b4c1128..f63c70f 100644
--- a/src/main/java/com/annimon/ownlang/lib/Arguments.java
+++ b/src/main/java/com/annimon/ownlang/lib/Arguments.java
@@ -4,6 +4,8 @@ import com.annimon.ownlang.exceptions.ArgumentsMismatchException;
 
 public final class Arguments {
 
+    private Arguments() { }
+
     public static void check(int expected, int got) {
         if (got != expected) throw new ArgumentsMismatchException(String.format(
                 "%d %s expected, got %d", expected, pluralize(expected), got));
diff --git a/src/main/java/com/annimon/ownlang/lib/CallStack.java b/src/main/java/com/annimon/ownlang/lib/CallStack.java
index e5b753b..c7517bd 100644
--- a/src/main/java/com/annimon/ownlang/lib/CallStack.java
+++ b/src/main/java/com/annimon/ownlang/lib/CallStack.java
@@ -5,7 +5,9 @@ import java.util.concurrent.ConcurrentLinkedDeque;
 
 public final class CallStack {
     
-    private static final Deque<CallInfo> calls = new ConcurrentLinkedDeque<CallInfo>();;
+    private static final Deque<CallInfo> calls = new ConcurrentLinkedDeque<>();
+
+    private CallStack() { }
     
     public static synchronized void clear() {
         calls.clear();
diff --git a/src/main/java/com/annimon/ownlang/lib/Functions.java b/src/main/java/com/annimon/ownlang/lib/Functions.java
index 8d18569..f43d029 100644
--- a/src/main/java/com/annimon/ownlang/lib/Functions.java
+++ b/src/main/java/com/annimon/ownlang/lib/Functions.java
@@ -15,6 +15,8 @@ public final class Functions {
         functions = new HashMap<>();
     }
 
+    private Functions() { }
+
     public static void clear() {
         functions.clear();
     }
diff --git a/src/main/java/com/annimon/ownlang/lib/NumberValue.java b/src/main/java/com/annimon/ownlang/lib/NumberValue.java
index 3febab7..68e005d 100644
--- a/src/main/java/com/annimon/ownlang/lib/NumberValue.java
+++ b/src/main/java/com/annimon/ownlang/lib/NumberValue.java
@@ -6,10 +6,15 @@ package com.annimon.ownlang.lib;
  */
 public final class NumberValue implements Value {
 
-    public static final NumberValue MINUS_ONE, ZERO, ONE;
+    private static final int CACHE_MIN = -128;
+    private static final int CACHE_MAX = 127;
+
+    public static final NumberValue MINUS_ONE;
+    public static final NumberValue ZERO;
+    public static final NumberValue ONE;
 
-    private static final int CACHE_MIN = -128, CACHE_MAX = 127;
     private static final NumberValue[] NUMBER_CACHE;
+
     static {
         final int length = CACHE_MAX - CACHE_MIN + 1;
         NUMBER_CACHE = new NumberValue[length];
diff --git a/src/main/java/com/annimon/ownlang/lib/Types.java b/src/main/java/com/annimon/ownlang/lib/Types.java
index a6da033..8c0b216 100644
--- a/src/main/java/com/annimon/ownlang/lib/Types.java
+++ b/src/main/java/com/annimon/ownlang/lib/Types.java
@@ -10,7 +10,8 @@ public final class Types {
             MAP = 4,
             FUNCTION = 5;
     
-    private static final int FIRST = OBJECT, LAST = FUNCTION;
+    private static final int FIRST = OBJECT;
+    private static final int LAST = FUNCTION;
     private static final String[] NAMES = {"object", "number", "string", "array", "map", "function"};
     
     public static String typeToString(int type) {
@@ -19,4 +20,6 @@ public final class Types {
         }
         return "unknown (" + type + ")";
     }
+
+    private Types() { }
 }
diff --git a/src/main/java/com/annimon/ownlang/lib/ValueUtils.java b/src/main/java/com/annimon/ownlang/lib/ValueUtils.java
index c11bbfb..5d051bc 100644
--- a/src/main/java/com/annimon/ownlang/lib/ValueUtils.java
+++ b/src/main/java/com/annimon/ownlang/lib/ValueUtils.java
@@ -8,6 +8,8 @@ import org.json.JSONObject;
 
 public final class ValueUtils {
 
+    private ValueUtils() { }
+
     public static Object toObject(Value val) {
         switch (val.type()) {
             case Types.ARRAY:
@@ -101,7 +103,7 @@ public final class ValueUtils {
         return result;
     }
 
-    public static Function consumeFunction(Value value, int argumentNumber) throws TypeException {
+    public static Function consumeFunction(Value value, int argumentNumber) {
         final int type = value.type();
         if (type != Types.FUNCTION) {
             throw new TypeException("Function expected at argument " + (argumentNumber + 1)
diff --git a/src/main/java/com/annimon/ownlang/lib/Variables.java b/src/main/java/com/annimon/ownlang/lib/Variables.java
index f827ec3..4c6f951 100644
--- a/src/main/java/com/annimon/ownlang/lib/Variables.java
+++ b/src/main/java/com/annimon/ownlang/lib/Variables.java
@@ -35,6 +35,8 @@ public final class Variables {
         Variables.clear();
     }
 
+    private Variables() { }
+
     public static Map<String, Value> variables() {
         return scope.variables;
     }
diff --git a/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java b/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java
index 973f4ae..e156802 100644
--- a/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java
+++ b/src/main/java/com/annimon/ownlang/modules/canvasfx/canvasfx.java
@@ -53,7 +53,7 @@ public final class canvasfx implements Module {
     private static GraphicsContext graphics;
     private static Canvas canvas;
     
-    private static enum Events {
+    private enum Events {
         DRAG_DETECTED(MouseEvent.DRAG_DETECTED),
         MOUSE_CLICKED(MouseEvent.MOUSE_CLICKED),
         MOUSE_DRAGGED(MouseEvent.MOUSE_DRAGGED),
diff --git a/src/main/java/com/annimon/ownlang/modules/files/files.java b/src/main/java/com/annimon/ownlang/modules/files/files.java
index 6637323..00947c4 100644
--- a/src/main/java/com/annimon/ownlang/modules/files/files.java
+++ b/src/main/java/com/annimon/ownlang/modules/files/files.java
@@ -156,7 +156,7 @@ public final class files implements Module {
         }
     }
     
-    private static abstract class FileFunction implements Function {
+    private abstract static class FileFunction implements Function {
         
         @Override
         public Value execute(Value... args) {
@@ -252,7 +252,7 @@ public final class files implements Module {
     private static class setExecutable extends FileFunction {
         @Override
         protected Value execute(FileInfo fileInfo, Value[] args) throws IOException {
-            final boolean ownerOnly = (args.length >= 3) ? (args[2].asInt() != 0) : true;
+            final boolean ownerOnly = (args.length < 3) || (args[2].asInt() != 0);
             return NumberValue.fromBoolean(
                     fileInfo.file.setExecutable(args[1].asInt() != 0, ownerOnly));
         }
@@ -261,7 +261,7 @@ public final class files implements Module {
     private static class setReadable extends FileFunction {
         @Override
         protected Value execute(FileInfo fileInfo, Value[] args) throws IOException {
-            final boolean ownerOnly = (args.length >= 3) ? (args[2].asInt() != 0) : true;
+            final boolean ownerOnly = (args.length < 3) || (args[2].asInt() != 0);
             return NumberValue.fromBoolean(
                     fileInfo.file.setReadable(args[1].asInt() != 0, ownerOnly));
         }
@@ -270,7 +270,7 @@ public final class files implements Module {
     private static class setWritable extends FileFunction {
         @Override
         protected Value execute(FileInfo fileInfo, Value[] args) throws IOException {
-            final boolean ownerOnly = (args.length >= 3) ? (args[2].asInt() != 0) : true;
+            final boolean ownerOnly = (args.length < 3) || (args[2].asInt() != 0);
             return NumberValue.fromBoolean(
                     fileInfo.file.setWritable(args[1].asInt() != 0, ownerOnly));
         }
diff --git a/src/main/java/com/annimon/ownlang/modules/forms/Components.java b/src/main/java/com/annimon/ownlang/modules/forms/Components.java
index 5d1b6b5..f283e5a 100644
--- a/src/main/java/com/annimon/ownlang/modules/forms/Components.java
+++ b/src/main/java/com/annimon/ownlang/modules/forms/Components.java
@@ -14,7 +14,9 @@ import javax.swing.SwingConstants;
  */
 public final class Components {
 
-    public static Value newWindow(Value... args) {
+    private Components() { }
+
+    static Value newWindow(Value... args) {
         Arguments.checkOrOr(0, 1, args.length);
         String title = (args.length == 1) ? args[0].asString() : "";
         final JFrame frame = new JFrame(title);
@@ -22,7 +24,7 @@ public final class Components {
         return new JFrameValue(frame);
     }
 
-    public static Value newPanel(Value... args) {
+    static Value newPanel(Value... args) {
         Arguments.checkOrOr(0, 1, args.length);
         final JPanel panel = new JPanel();
         if (args.length == 1) {
@@ -31,20 +33,20 @@ public final class Components {
         return new JPanelValue(panel);
     }
 
-    public static Value newButton(Value... args) {
+    static Value newButton(Value... args) {
         Arguments.checkOrOr(0, 1, args.length);
         String text = (args.length == 1) ? args[0].asString() : "";
         return new JButtonValue(new JButton(text));
     }
 
-    public static Value newLabel(Value... args) {
+    static Value newLabel(Value... args) {
         Arguments.checkRange(0, 2, args.length);
         String text = (args.length >= 1) ? args[0].asString() : "";
         int align = (args.length == 2) ? args[1].asInt() : SwingConstants.LEADING;
         return new JLabelValue(new JLabel(text, align));
     }
 
-    public static Value newTextField(Value... args) {
+    static Value newTextField(Value... args) {
         Arguments.checkOrOr(0, 1, args.length);
         String text = (args.length == 1) ? args[0].asString() : "";
         return new JTextFieldValue(new JTextField(text));
diff --git a/src/main/java/com/annimon/ownlang/modules/forms/LayoutManagers.java b/src/main/java/com/annimon/ownlang/modules/forms/LayoutManagers.java
index 8191e69..45558f2 100644
--- a/src/main/java/com/annimon/ownlang/modules/forms/LayoutManagers.java
+++ b/src/main/java/com/annimon/ownlang/modules/forms/LayoutManagers.java
@@ -13,7 +13,9 @@ import javax.swing.BoxLayout;
  */
 public final class LayoutManagers {
 
-    public static Value borderLayout(Value... args) {
+    private LayoutManagers() { }
+
+    static Value borderLayout(Value... args) {
         Arguments.checkOrOr(0, 2, args.length);
         int hgap = (args.length == 2) ? args[0].asInt() : 0;
         int vgap = (args.length == 2) ? args[1].asInt() : 0;
@@ -22,7 +24,7 @@ public final class LayoutManagers {
         );
     }
 
-    public static Value boxLayout(Value... args) {
+    static Value boxLayout(Value... args) {
         Arguments.checkOrOr(1, 2, args.length);
         int axis = (args.length == 2) ? args[1].asInt() : BoxLayout.PAGE_AXIS;
         return new LayoutManagerValue(
@@ -30,7 +32,7 @@ public final class LayoutManagers {
         );
     }
 
-    public static Value cardLayout(Value... args) {
+    static Value cardLayout(Value... args) {
         Arguments.checkOrOr(0, 2, args.length);
         int hgap = (args.length == 2) ? args[0].asInt() : 0;
         int vgap = (args.length == 2) ? args[1].asInt() : 0;
@@ -39,7 +41,7 @@ public final class LayoutManagers {
         );
     }
 
-    public static Value gridLayout(Value... args) {
+    static Value gridLayout(Value... args) {
         Arguments.checkRange(0, 4, args.length);
         int rows = 1, cols = 0, hgap = 0, vgap = 0;
         switch (args.length) {
@@ -67,7 +69,7 @@ public final class LayoutManagers {
         );
     }
 
-    public static Value flowLayout(Value... args) {
+    static Value flowLayout(Value... args) {
         Arguments.checkRange(0, 3, args.length);
         final int align, hgap, vgap;
         switch (args.length) {
diff --git a/src/main/java/com/annimon/ownlang/modules/functional/functional_filter.java b/src/main/java/com/annimon/ownlang/modules/functional/functional_filter.java
index d0e631b..c4749ce 100644
--- a/src/main/java/com/annimon/ownlang/modules/functional/functional_filter.java
+++ b/src/main/java/com/annimon/ownlang/modules/functional/functional_filter.java
@@ -36,7 +36,7 @@ public final class functional_filter implements Function {
     
     private Value filterArray(ArrayValue array, Function predicate, boolean takeWhile) {
         final int size = array.size();
-        final List<Value> values = new ArrayList<Value>(size);
+        final List<Value> values = new ArrayList<>(size);
         for (Value value : array) {
             if (predicate.execute(value) != NumberValue.ZERO) {
                 values.add(value);
diff --git a/src/main/java/com/annimon/ownlang/modules/http/http_http.java b/src/main/java/com/annimon/ownlang/modules/http/http_http.java
index bddc3c5..a247a41 100644
--- a/src/main/java/com/annimon/ownlang/modules/http/http_http.java
+++ b/src/main/java/com/annimon/ownlang/modules/http/http_http.java
@@ -144,9 +144,10 @@ public final class http_http implements Function {
         return getStringRequestBody(params, options);
     }
     
-    private RequestBody getMapRequestBody(MapValue params, MapValue options) throws UnsupportedEncodingException {
+    private RequestBody getMapRequestBody(MapValue params, MapValue options) {
         final FormBody.Builder form = new FormBody.Builder();
-        final boolean alreadyEncoded = (options.containsKey(ENCODED_KEY) && options.get(ENCODED_KEY).asInt() != 0);
+        final boolean alreadyEncoded = (options.containsKey(ENCODED_KEY)
+                && options.get(ENCODED_KEY).asInt() != 0);
         for (Map.Entry<Value, Value> param : params) {
             final String name = param.getKey().asString();
             final String value = param.getValue().asString();
diff --git a/src/main/java/com/annimon/ownlang/modules/java/java.java b/src/main/java/com/annimon/ownlang/modules/java/java.java
index d236fc3..953ae2c 100644
--- a/src/main/java/com/annimon/ownlang/modules/java/java.java
+++ b/src/main/java/com/annimon/ownlang/modules/java/java.java
@@ -283,7 +283,7 @@ public final class java implements Module {
                     methods.add(method);
                 }
             }
-            if (methods.size() == 0) {
+            if (methods.isEmpty()) {
                 return FunctionValue.EMPTY;
             }
             return new FunctionValue(methodsToFunction(object, methods));
@@ -362,7 +362,7 @@ public final class java implements Module {
     }
 
     private static Value objectToValue(Class<?> clazz, Object o) {
-        if (o == null | o == NULL) return NULL;
+        if (o == null || o == NULL) return NULL;
         if (clazz.isPrimitive()) {
             if (int.class.isAssignableFrom(clazz))
                 return NumberValue.of((int) o);
@@ -394,48 +394,7 @@ public final class java implements Module {
             return (Value) o;
         }
         if (clazz.isArray()) {
-            final int length = Array.getLength(o);
-            final ArrayValue result = new ArrayValue(length);
-            final Class<?> componentType = clazz.getComponentType();
-            int i = 0;
-            if (boolean.class.isAssignableFrom(componentType)) {
-                for (boolean element : (boolean[]) o) {
-                    result.set(i++, NumberValue.fromBoolean(element));
-                }
-            } else if (byte.class.isAssignableFrom(componentType)) {
-                for (byte element : (byte[]) o) {
-                    result.set(i++, NumberValue.of(element));
-                }
-            } else if (char.class.isAssignableFrom(componentType)) {
-                for (char element : (char[]) o) {
-                    result.set(i++, NumberValue.of(element));
-                }
-            } else if (double.class.isAssignableFrom(componentType)) {
-                for (double element : (double[]) o) {
-                    result.set(i++, NumberValue.of(element));
-                }
-            } else if (float.class.isAssignableFrom(componentType)) {
-                for (float element : (float[]) o) {
-                    result.set(i++, NumberValue.of(element));
-                }
-            } else if (int.class.isAssignableFrom(componentType)) {
-                for (int element : (int[]) o) {
-                    result.set(i++, NumberValue.of(element));
-                }
-            } else if (long.class.isAssignableFrom(componentType)) {
-                for (long element : (long[]) o) {
-                    result.set(i++, NumberValue.of(element));
-                }
-            } else if (short.class.isAssignableFrom(componentType)) {
-                for (short element : (short[]) o) {
-                    result.set(i++, NumberValue.of(element));
-                }
-            } else {
-                for (Object element : (Object[]) o) {
-                    result.set(i++, objectToValue(element));
-                }
-            }
-            return result;
+            return arrayToValue(clazz, o);
         }
         final Class<?> componentType = clazz.getComponentType();
         if (componentType != null) {
@@ -444,6 +403,51 @@ public final class java implements Module {
         return new ObjectValue(o);
     }
 
+    private static Value arrayToValue(Class<?> clazz, Object o) {
+        final int length = Array.getLength(o);
+        final ArrayValue result = new ArrayValue(length);
+        final Class<?> componentType = clazz.getComponentType();
+        int i = 0;
+        if (boolean.class.isAssignableFrom(componentType)) {
+            for (boolean element : (boolean[]) o) {
+                result.set(i++, NumberValue.fromBoolean(element));
+            }
+        } else if (byte.class.isAssignableFrom(componentType)) {
+            for (byte element : (byte[]) o) {
+                result.set(i++, NumberValue.of(element));
+            }
+        } else if (char.class.isAssignableFrom(componentType)) {
+            for (char element : (char[]) o) {
+                result.set(i++, NumberValue.of(element));
+            }
+        } else if (double.class.isAssignableFrom(componentType)) {
+            for (double element : (double[]) o) {
+                result.set(i++, NumberValue.of(element));
+            }
+        } else if (float.class.isAssignableFrom(componentType)) {
+            for (float element : (float[]) o) {
+                result.set(i++, NumberValue.of(element));
+            }
+        } else if (int.class.isAssignableFrom(componentType)) {
+            for (int element : (int[]) o) {
+                result.set(i++, NumberValue.of(element));
+            }
+        } else if (long.class.isAssignableFrom(componentType)) {
+            for (long element : (long[]) o) {
+                result.set(i++, NumberValue.of(element));
+            }
+        } else if (short.class.isAssignableFrom(componentType)) {
+            for (short element : (short[]) o) {
+                result.set(i++, NumberValue.of(element));
+            }
+        } else {
+            for (Object element : (Object[]) o) {
+                result.set(i++, objectToValue(element));
+            }
+        }
+        return result;
+    }
+
     private static Object[] valuesToObjects(Value[] args) {
         Object[] result = new Object[args.length];
         for (int i = 0; i < args.length; i++) {
@@ -459,15 +463,8 @@ public final class java implements Module {
                 return value.raw();
             case Types.STRING:
                 return value.asString();
-            case Types.ARRAY: {
-                final ArrayValue array = (ArrayValue) value;
-                final int size = array.size();
-                final Object[] result = new Object[size];
-                for (int i = 0; i < size; i++) {
-                    result[i] = valueToObject(array.get(i));
-                }
-                return result;
-            }
+            case Types.ARRAY:
+                return arrayToObject((ArrayValue) value);
         }
         if (value instanceof ObjectValue) {
             return ((ObjectValue) value).object;
@@ -477,5 +474,14 @@ public final class java implements Module {
         }
         return value.raw();
     }
+
+    private static Object arrayToObject(ArrayValue value) {
+        final int size = value.size();
+        final Object[] result = new Object[size];
+        for (int i = 0; i < size; i++) {
+            result[i] = valueToObject(value.get(i));
+        }
+        return result;
+    }
 //</editor-fold>
 }
diff --git a/src/main/java/com/annimon/ownlang/modules/jdbc/jdbc.java b/src/main/java/com/annimon/ownlang/modules/jdbc/jdbc.java
index 9518e7c..3bb3c78 100644
--- a/src/main/java/com/annimon/ownlang/modules/jdbc/jdbc.java
+++ b/src/main/java/com/annimon/ownlang/modules/jdbc/jdbc.java
@@ -430,7 +430,7 @@ public final class jdbc implements Module {
             set("getBigDecimal", getObjectResult(rs::getBigDecimal, rs::getBigDecimal, (bd) -> new StringValue(bd.toString())));
             set("getBoolean", getBooleanResult(rs::getBoolean, rs::getBoolean));
             set("getByte", getNumberResult(rs::getByte, rs::getByte));
-            set("getBytes", getObjectResult(rs::getBytes, rs::getBytes, (bytes) -> ArrayValue.of(bytes)));
+            set("getBytes", getObjectResult(rs::getBytes, rs::getBytes, ArrayValue::of));
             set("getDate", getObjectResult(rs::getDate, rs::getDate, (date) -> NumberValue.of(date.getTime())));
             set("getDouble", getNumberResult(rs::getDouble, rs::getDouble));
             set("getFloat", getNumberResult(rs::getFloat, rs::getFloat));
diff --git a/src/main/java/com/annimon/ownlang/modules/robot/robot.java b/src/main/java/com/annimon/ownlang/modules/robot/robot.java
index 0d3fa8e..901c7bd 100644
--- a/src/main/java/com/annimon/ownlang/modules/robot/robot.java
+++ b/src/main/java/com/annimon/ownlang/modules/robot/robot.java
@@ -8,6 +8,7 @@ import java.awt.event.InputEvent;
 import java.awt.event.KeyEvent;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.function.IntConsumer;
 
 /**
  *
@@ -83,12 +84,7 @@ public final class robot implements Module {
         }
     }
     
-    @FunctionalInterface
-    private interface RobotIntConsumer {
-        void accept(int value) throws IllegalArgumentException;
-    }
-    
-    private static Function convertFunction(RobotIntConsumer consumer) {
+    private static Function convertFunction(IntConsumer consumer) {
         return args -> {
             Arguments.check(1, args.length);
             try {
diff --git a/src/main/java/com/annimon/ownlang/modules/robot/robot_exec.java b/src/main/java/com/annimon/ownlang/modules/robot/robot_exec.java
index abdf545..322dde1 100644
--- a/src/main/java/com/annimon/ownlang/modules/robot/robot_exec.java
+++ b/src/main/java/com/annimon/ownlang/modules/robot/robot_exec.java
@@ -1,6 +1,5 @@
 package com.annimon.ownlang.modules.robot;
 
-import com.annimon.ownlang.Console;
 import com.annimon.ownlang.lib.Arguments;
 import com.annimon.ownlang.lib.ArrayValue;
 import com.annimon.ownlang.lib.Function;
@@ -10,7 +9,7 @@ import com.annimon.ownlang.lib.Value;
 
 public final class robot_exec implements Function {
     
-    public static enum Mode { EXEC, EXEC_AND_WAIT };
+    public enum Mode { EXEC, EXEC_AND_WAIT }
     
     private final Mode mode;
 
diff --git a/src/main/java/com/annimon/ownlang/modules/std/NumberFunctions.java b/src/main/java/com/annimon/ownlang/modules/std/NumberFunctions.java
index 31d2cd6..743732e 100644
--- a/src/main/java/com/annimon/ownlang/modules/std/NumberFunctions.java
+++ b/src/main/java/com/annimon/ownlang/modules/std/NumberFunctions.java
@@ -8,7 +8,9 @@ import com.annimon.ownlang.lib.Value;
 
 public final class NumberFunctions {
 
-    public static Value toHexString(Value... args) {
+    private NumberFunctions() { }
+
+    static Value toHexString(Value... args) {
         Arguments.check(1, args.length);
         long value;
         if (args[0].type() == Types.NUMBER) {
diff --git a/src/main/java/com/annimon/ownlang/modules/std/StringFunctions.java b/src/main/java/com/annimon/ownlang/modules/std/StringFunctions.java
index b9b5794..d850d6d 100644
--- a/src/main/java/com/annimon/ownlang/modules/std/StringFunctions.java
+++ b/src/main/java/com/annimon/ownlang/modules/std/StringFunctions.java
@@ -6,13 +6,15 @@ import com.annimon.ownlang.lib.Value;
 
 public final class StringFunctions {
 
-    public static Value parseInt(Value... args) {
+    private StringFunctions() { }
+
+    static Value parseInt(Value... args) {
         Arguments.checkOrOr(1, 2, args.length);
         final int radix = (args.length == 2) ? args[1].asInt() : 10;
         return NumberValue.of(Integer.parseInt(args[0].asString(), radix));
     }
 
-    public static Value parseLong(Value... args) {
+    static Value parseLong(Value... args) {
         Arguments.checkOrOr(1, 2, args.length);
         final int radix = (args.length == 2) ? args[1].asInt() : 10;
         return NumberValue.of(Long.parseLong(args[0].asString(), radix));
diff --git a/src/main/java/com/annimon/ownlang/modules/std/std_split.java b/src/main/java/com/annimon/ownlang/modules/std/std_split.java
index d0e1b5e..0c2c468 100644
--- a/src/main/java/com/annimon/ownlang/modules/std/std_split.java
+++ b/src/main/java/com/annimon/ownlang/modules/std/std_split.java
@@ -3,7 +3,6 @@ package com.annimon.ownlang.modules.std;
 import com.annimon.ownlang.lib.Arguments;
 import com.annimon.ownlang.lib.ArrayValue;
 import com.annimon.ownlang.lib.Function;
-import com.annimon.ownlang.lib.StringValue;
 import com.annimon.ownlang.lib.Value;
 
 public final class std_split implements Function {
diff --git a/src/main/java/com/annimon/ownlang/modules/yaml/yaml_decode.java b/src/main/java/com/annimon/ownlang/modules/yaml/yaml_decode.java
index fa3d3fc..07e3f19 100644
--- a/src/main/java/com/annimon/ownlang/modules/yaml/yaml_decode.java
+++ b/src/main/java/com/annimon/ownlang/modules/yaml/yaml_decode.java
@@ -13,8 +13,7 @@ public final class yaml_decode implements Function {
         try {
             final String yamlRaw = args[0].asString();
             final Object root = new Yaml().load(yamlRaw);
-            final Value process = process(root);
-            return process;
+            return process(root);
         } catch (Exception ex) {
             throw new RuntimeException("Error while parsing yaml", ex);
         }
diff --git a/src/main/java/com/annimon/ownlang/parser/Lexer.java b/src/main/java/com/annimon/ownlang/parser/Lexer.java
index e0ca7ab..2a64477 100644
--- a/src/main/java/com/annimon/ownlang/parser/Lexer.java
+++ b/src/main/java/com/annimon/ownlang/parser/Lexer.java
@@ -87,7 +87,7 @@ public final class Lexer {
     
     private static final Map<String, TokenType> KEYWORDS;
     static {
-        KEYWORDS = new HashMap<String, TokenType>();
+        KEYWORDS = new HashMap<>();
         KEYWORDS.put("print", TokenType.PRINT);
         KEYWORDS.put("println", TokenType.PRINTLN);
         KEYWORDS.put("if", TokenType.IF);
diff --git a/src/main/java/com/annimon/ownlang/parser/Optimizer.java b/src/main/java/com/annimon/ownlang/parser/Optimizer.java
index a41da8d..a4f2ff6 100644
--- a/src/main/java/com/annimon/ownlang/parser/Optimizer.java
+++ b/src/main/java/com/annimon/ownlang/parser/Optimizer.java
@@ -13,6 +13,8 @@ import com.annimon.ownlang.parser.optimization.SummaryOptimization;
 
 public final class Optimizer {
 
+    private Optimizer() { }
+
     public static Statement optimize(Statement statement, int level, boolean showSummary) {
         if (level == 0) return statement;
 
diff --git a/src/main/java/com/annimon/ownlang/parser/Parser.java b/src/main/java/com/annimon/ownlang/parser/Parser.java
index f461a77..2f5a270 100644
--- a/src/main/java/com/annimon/ownlang/parser/Parser.java
+++ b/src/main/java/com/annimon/ownlang/parser/Parser.java
@@ -6,6 +6,7 @@ import com.annimon.ownlang.lib.StringValue;
 import com.annimon.ownlang.lib.UserDefinedFunction;
 import com.annimon.ownlang.parser.ast.*;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.List;
@@ -305,7 +306,7 @@ public final class Parser {
         }
         if (lookMatch(0, TokenType.DOT)) {
             final List<Expression> indices = variableSuffix();
-            if (indices == null || indices.isEmpty()) return expr;
+            if (indices.isEmpty()) return expr;
 
             if (lookMatch(0, TokenType.LPAREN)) {
                 // next function call
@@ -441,7 +442,7 @@ public final class Parser {
     private Expression assignmentStrict() {
         final int position = pos;
         final Expression targetExpr = qualifiedName();
-        if ((targetExpr == null) || !(targetExpr instanceof Accessible)) {
+        if (!(targetExpr instanceof Accessible)) {
             pos = position;
             return null;
         }
@@ -746,7 +747,7 @@ public final class Parser {
         if (!match(TokenType.WORD)) return null;
         
         final List<Expression> indices = variableSuffix();
-        if ((indices == null) || indices.isEmpty()) {
+        if (indices.isEmpty()) {
             return new VariableExpression(current.getText());
         }
         return new ContainerAccessExpression(current.getText(), indices);
@@ -755,7 +756,7 @@ public final class Parser {
     private List<Expression> variableSuffix() {
         // .key1.arr1[expr1][expr2].key2
         if (!lookMatch(0, TokenType.DOT) && !lookMatch(0, TokenType.LBRACKET)) {
-            return null;
+            return Collections.emptyList();
         }
         final List<Expression> indices = new ArrayList<>();
         while (lookMatch(0, TokenType.DOT) || lookMatch(0, TokenType.LBRACKET)) {
diff --git a/src/main/java/com/annimon/ownlang/parser/SourceLoader.java b/src/main/java/com/annimon/ownlang/parser/SourceLoader.java
index 9545b52..67e49cf 100644
--- a/src/main/java/com/annimon/ownlang/parser/SourceLoader.java
+++ b/src/main/java/com/annimon/ownlang/parser/SourceLoader.java
@@ -7,6 +7,8 @@ import java.io.InputStream;
 
 public final class SourceLoader {
 
+    private SourceLoader() { }
+
     public static String readSource(String name) throws IOException {
         InputStream is = SourceLoader.class.getResourceAsStream(name);
         if (is != null) return readAndCloseStream(is);
@@ -19,9 +21,9 @@ public final class SourceLoader {
         final ByteArrayOutputStream result = new ByteArrayOutputStream();
         final int bufferSize = 1024;
         final byte[] buffer = new byte[bufferSize];
-        int readed;
-        while ((readed = is.read(buffer)) != -1) {
-            result.write(buffer, 0, readed);
+        int read;
+        while ((read = is.read(buffer)) != -1) {
+            result.write(buffer, 0, read);
         }
         is.close();
         return result.toString("UTF-8");
diff --git a/src/main/java/com/annimon/ownlang/parser/ast/BinaryExpression.java b/src/main/java/com/annimon/ownlang/parser/ast/BinaryExpression.java
index 3749ae7..999e94e 100644
--- a/src/main/java/com/annimon/ownlang/parser/ast/BinaryExpression.java
+++ b/src/main/java/com/annimon/ownlang/parser/ast/BinaryExpression.java
@@ -16,7 +16,7 @@ import com.annimon.ownlang.lib.Value;
  */
 public final class BinaryExpression implements Expression {
     
-    public static enum Operator {
+    public enum Operator {
         ADD("+"),
         SUBTRACT("-"),
         MULTIPLY("*"),
@@ -40,7 +40,7 @@ public final class BinaryExpression implements Expression {
         
         private final String name;
 
-        private Operator(String name) {
+        Operator(String name) {
             this.name = name;
         }
 
@@ -73,7 +73,7 @@ public final class BinaryExpression implements Expression {
         }
     }
     
-    private Value eval(Value value1, Value value2) throws OperationIsNotSupportedException {
+    private Value eval(Value value1, Value value2) {
         switch (operation) {
             case ADD: return add(value1, value2);
             case SUBTRACT: return subtract(value1, value2);
@@ -141,7 +141,8 @@ public final class BinaryExpression implements Expression {
         switch (value1.type()) {
             case Types.NUMBER: return subtract((NumberValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -177,17 +178,10 @@ public final class BinaryExpression implements Expression {
     private Value multiply(Value value1, Value value2) {
         switch (value1.type()) {
             case Types.NUMBER: return multiply((NumberValue) value1, value2);
-            case Types.STRING: {
-                final String string1 = value1.asString();
-                final int iterations = value2.asInt();
-                final StringBuilder buffer = new StringBuilder();
-                for (int i = 0; i < iterations; i++) {
-                    buffer.append(string1);
-                }
-                return new StringValue(buffer.toString());
-            }
+            case Types.STRING: return multiply((StringValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -219,12 +213,23 @@ public final class BinaryExpression implements Expression {
         }
         return NumberValue.of(number1.intValue() * value2.asInt());
     }
+
+    private Value multiply(StringValue value1, Value value2) {
+        final String string1 = value1.asString();
+        final int iterations = value2.asInt();
+        final StringBuilder buffer = new StringBuilder();
+        for (int i = 0; i < iterations; i++) {
+            buffer.append(string1);
+        }
+        return new StringValue(buffer.toString());
+    }
     
     private Value divide(Value value1, Value value2) {
         switch (value1.type()) {
             case Types.NUMBER: return divide((NumberValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -261,7 +266,8 @@ public final class BinaryExpression implements Expression {
         switch (value1.type()) {
             case Types.NUMBER: return remainder((NumberValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -298,7 +304,8 @@ public final class BinaryExpression implements Expression {
         switch (value1.type()) {
             case Types.ARRAY: return ArrayValue.add((ArrayValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -306,7 +313,8 @@ public final class BinaryExpression implements Expression {
         switch (value1.type()) {
             case Types.NUMBER: return and((NumberValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -331,7 +339,8 @@ public final class BinaryExpression implements Expression {
         switch (value1.type()) {
             case Types.NUMBER: return or((NumberValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -356,7 +365,8 @@ public final class BinaryExpression implements Expression {
         switch (value1.type()) {
             case Types.NUMBER: return xor((NumberValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -380,16 +390,13 @@ public final class BinaryExpression implements Expression {
     private Value lshift(Value value1, Value value2) {
         switch (value1.type()) {
             case Types.NUMBER: return lshift((NumberValue) value1, value2);
-            case Types.ARRAY: {
-                if (value2.type() != Types.ARRAY)
-                    throw new TypeException("Cannot merge non array value to array");
-                return ArrayValue.merge((ArrayValue) value1, (ArrayValue) value2);
-            }
+            case Types.ARRAY: return lshift((ArrayValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
-    
+
     private Value lshift(NumberValue value1, Value value2) {
         final Number number1 = value1.raw();
         if (value2.type() == Types.NUMBER) {
@@ -406,12 +413,19 @@ public final class BinaryExpression implements Expression {
         }
         return NumberValue.of(number1.intValue() << value2.asInt());
     }
+
+    private Value lshift(ArrayValue value1, Value value2) {
+        if (value2.type() != Types.ARRAY)
+            throw new TypeException("Cannot merge non array value to array");
+        return ArrayValue.merge(value1, (ArrayValue) value2);
+    }
     
     private Value rshift(Value value1, Value value2) {
         switch (value1.type()) {
             case Types.NUMBER: return rshift((NumberValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
@@ -436,7 +450,8 @@ public final class BinaryExpression implements Expression {
         switch (value1.type()) {
             case Types.NUMBER: return urshift((NumberValue) value1, value2);
             default:
-                throw new OperationIsNotSupportedException(operation, "for " + Types.typeToString(value1.type()));
+                throw new OperationIsNotSupportedException(operation,
+                        "for " + Types.typeToString(value1.type()));
         }
     }
     
diff --git a/src/main/java/com/annimon/ownlang/parser/ast/ConditionalExpression.java b/src/main/java/com/annimon/ownlang/parser/ast/ConditionalExpression.java
index 1ee8925..b39d796 100644
--- a/src/main/java/com/annimon/ownlang/parser/ast/ConditionalExpression.java
+++ b/src/main/java/com/annimon/ownlang/parser/ast/ConditionalExpression.java
@@ -11,7 +11,7 @@ import com.annimon.ownlang.lib.Value;
  */
 public final class ConditionalExpression implements Expression {
     
-    public static enum Operator {
+    public enum Operator {
         EQUALS("=="),
         NOT_EQUALS("!="),
         
diff --git a/src/main/java/com/annimon/ownlang/parser/ast/MatchExpression.java b/src/main/java/com/annimon/ownlang/parser/ast/MatchExpression.java
index 14dd026..4a33440 100644
--- a/src/main/java/com/annimon/ownlang/parser/ast/MatchExpression.java
+++ b/src/main/java/com/annimon/ownlang/parser/ast/MatchExpression.java
@@ -205,7 +205,7 @@ public final class MatchExpression extends InterruptableNode implements Expressi
         return sb.toString();
     }
 
-    public static abstract class Pattern {
+    public abstract static class Pattern {
         public Statement result;
         public Expression optCondition;
 
diff --git a/src/main/java/com/annimon/ownlang/parser/ast/UnaryExpression.java b/src/main/java/com/annimon/ownlang/parser/ast/UnaryExpression.java
index f7d4839..551ba6a 100644
--- a/src/main/java/com/annimon/ownlang/parser/ast/UnaryExpression.java
+++ b/src/main/java/com/annimon/ownlang/parser/ast/UnaryExpression.java
@@ -12,7 +12,7 @@ import com.annimon.ownlang.lib.Value;
  */
 public final class UnaryExpression implements Expression, Statement {
 
-    public static enum Operator {
+    public enum Operator {
         INCREMENT_PREFIX("++"),
         DECREMENT_PREFIX("--"),
         INCREMENT_POSTFIX("++"),
diff --git a/src/main/java/com/annimon/ownlang/parser/optimization/OptimizationVisitor.java b/src/main/java/com/annimon/ownlang/parser/optimization/OptimizationVisitor.java
index 46696ad..8db0e84 100644
--- a/src/main/java/com/annimon/ownlang/parser/optimization/OptimizationVisitor.java
+++ b/src/main/java/com/annimon/ownlang/parser/optimization/OptimizationVisitor.java
@@ -260,16 +260,14 @@ public abstract class OptimizationVisitor<T> implements ResultVisitor<Node, T> {
                 final String variable = ((MatchExpression.VariablePattern) pattern).variable;
                 final VariableExpression expr = new VariableExpression(variable);
                 final Node node = expr.accept(this, t);
-                if (node != expr) {
-                    if (isValue(node)) {
-                        changed = true;
-                        final Value value = ((ValueExpression) node).value;
-                        final Expression optCondition = pattern.optCondition;
-                        final Statement result = pattern.result;
-                        pattern = new MatchExpression.ConstantPattern(value);
-                        pattern.optCondition = optCondition;
-                        pattern.result = result;
-                    }
+                if ((node != expr) && isValue(node)) {
+                    changed = true;
+                    final Value value = ((ValueExpression) node).value;
+                    final Expression optCondition = pattern.optCondition;
+                    final Statement result = pattern.result;
+                    pattern = new MatchExpression.ConstantPattern(value);
+                    pattern.optCondition = optCondition;
+                    pattern.result = result;
                 }
             }
             
diff --git a/src/main/java/com/annimon/ownlang/parser/visitors/PrintVisitor.java b/src/main/java/com/annimon/ownlang/parser/visitors/PrintVisitor.java
index 4ecc6f0..2e0f9ca 100644
--- a/src/main/java/com/annimon/ownlang/parser/visitors/PrintVisitor.java
+++ b/src/main/java/com/annimon/ownlang/parser/visitors/PrintVisitor.java
@@ -34,7 +34,7 @@ public class PrintVisitor implements ResultVisitor<StringBuilder, StringBuilder>
 
     @Override
     public StringBuilder visit(AssignmentExpression s, StringBuilder t) {
-        ((Node) s.target).accept(this, t);
+        s.target.accept(this, t);
         t.append(' ').append((s.operation == null) ? "" : s.operation);
         t.append("= ");
         s.expression.accept(this, t);
@@ -203,7 +203,8 @@ public class PrintVisitor implements ResultVisitor<StringBuilder, StringBuilder>
 
     @Override
     public StringBuilder visit(FunctionalExpression s, StringBuilder t) {
-        if (s.functionExpr instanceof ValueExpression && ((ValueExpression)s.functionExpr).value.type() == Types.STRING) {
+        if (s.functionExpr instanceof ValueExpression
+                && ((ValueExpression)s.functionExpr).value.type() == Types.STRING) {
             t.append(((ValueExpression)s.functionExpr).value.asString());
         } else {
             s.functionExpr.accept(this, t);
diff --git a/src/main/java/com/annimon/ownlang/parser/visitors/VisitorUtils.java b/src/main/java/com/annimon/ownlang/parser/visitors/VisitorUtils.java
index 408e569..1c593b8 100644
--- a/src/main/java/com/annimon/ownlang/parser/visitors/VisitorUtils.java
+++ b/src/main/java/com/annimon/ownlang/parser/visitors/VisitorUtils.java
@@ -17,6 +17,8 @@ import java.util.Set;
 
 public final class VisitorUtils {
 
+    private VisitorUtils() { }
+
     public static boolean isValue(Node node) {
         return (node instanceof ValueExpression);
     }
diff --git a/src/main/java/com/annimon/ownlang/utils/ModulesInfoCreator.java b/src/main/java/com/annimon/ownlang/utils/ModulesInfoCreator.java
index 420ec0b..b9ec788 100644
--- a/src/main/java/com/annimon/ownlang/utils/ModulesInfoCreator.java
+++ b/src/main/java/com/annimon/ownlang/utils/ModulesInfoCreator.java
@@ -7,19 +7,10 @@ import com.annimon.ownlang.lib.Value;
 import com.annimon.ownlang.lib.Variables;
 import com.annimon.ownlang.modules.Module;
 import java.io.File;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.HashMap;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import org.json.JSONArray;
-import org.json.JSONException;
 import org.json.JSONObject;
 import org.yaml.snakeyaml.DumperOptions;
 import org.yaml.snakeyaml.Yaml;
@@ -28,14 +19,17 @@ public final class ModulesInfoCreator {
 
     private static final String MODULES_PATH = "src/main/java/com/annimon/ownlang/modules";
 
-    public static void main(String[] args) throws InstantiationException, IllegalAccessException, ClassNotFoundException {
+    public static void main(String[] args)
+            throws InstantiationException, IllegalAccessException, ClassNotFoundException {
         final Class<Module> clazz = Module.class; // get classloader for package
 
         final List<ModuleInfo> moduleInfos = new ArrayList<>();
 
-        String[] moduleNames = Arrays.stream(new File(MODULES_PATH).listFiles())
-                .filter(p -> p.isDirectory())
-                .map(p -> p.getName())
+        String[] moduleNames = Optional.ofNullable(new File(MODULES_PATH).listFiles())
+                .map(Arrays::stream)
+                .orElse(Stream.empty())
+                .filter(File::isDirectory)
+                .map(File::getName)
                 .toArray(String[]::new);
         for (String moduleName : moduleNames) {
             final String moduleClassPath = String.format("com.annimon.ownlang.modules.%s.%s", moduleName, moduleName);
@@ -57,16 +51,16 @@ public final class ModulesInfoCreator {
 
         System.out.println("Total modules: " + moduleInfos.size());
         System.out.println("Total functions: " + moduleInfos.stream()
-                .flatMap(m -> m.functions.stream())
-                .count()
+                .mapToLong(m -> m.functions.size())
+                .sum()
         );
         System.out.println("Total constants: " + moduleInfos.stream()
-                .flatMap(m -> m.constants.keySet().stream())
-                .count()
+                .mapToLong(m -> m.constants.keySet().size())
+                .sum()
         );
     }
 
-    private static void printAsJson(List<ModuleInfo> moduleInfos) throws JSONException {
+    private static void printAsJson(List<ModuleInfo> moduleInfos) {
         final JSONArray modulesJson = new JSONArray();
         for (ModuleInfo moduleInfo : moduleInfos) {
             modulesJson.put(new JSONObject(moduleInfo.info()));
@@ -128,7 +122,7 @@ public final class ModulesInfoCreator {
         public List<Map<String, Object>> constants() {
             final List<Map<String, Object>> result = new ArrayList<>();
             constants.entrySet().stream()
-                    .sorted(Comparator.comparing(e -> e.getKey()))
+                    .sorted(Comparator.comparing(Map.Entry::getKey))
                     .forEach(entry -> {
                 final Value value = entry.getValue();
 
@@ -140,7 +134,7 @@ public final class ModulesInfoCreator {
                     String text = ((Map<Value, Value>) value.raw()).entrySet().stream()
                             .sorted(Comparator.comparing(
                                     e -> ((MapValue)value).size() > 16 ? e.getKey() : e.getValue()))
-                            .map(s -> s.toString())
+                            .map(Object::toString)
                             .collect(Collectors.joining(", ", "{", "}"));
                     constant.put("value", text);
                 } else {
diff --git a/src/main/java/com/annimon/ownlang/utils/OptimizationDumper.java b/src/main/java/com/annimon/ownlang/utils/OptimizationDumper.java
index 45df8bb..c4d7797 100644
--- a/src/main/java/com/annimon/ownlang/utils/OptimizationDumper.java
+++ b/src/main/java/com/annimon/ownlang/utils/OptimizationDumper.java
@@ -68,7 +68,6 @@ public final class OptimizationDumper {
     }
 
     private static String nodeToString(Node n) {
-//        return n.toString();
         return n.accept(new PrintVisitor(), new StringBuilder()).toString();
     }
 
diff --git a/src/main/java/com/annimon/ownlang/utils/Repl.java b/src/main/java/com/annimon/ownlang/utils/Repl.java
index e56e0ac..2c06f94 100644
--- a/src/main/java/com/annimon/ownlang/utils/Repl.java
+++ b/src/main/java/com/annimon/ownlang/utils/Repl.java
@@ -129,7 +129,8 @@ public final class Repl {
 
         int maxLength = commands.stream()
                 .mapToInt(String::length)
-                .max().getAsInt();
+                .max()
+                .orElse(20);
 
         final int maxCols = 2;
         final int size = commands.size();
diff --git a/src/test/java/com/annimon/ownlang/parser/LexerBenchmarkTest.java b/src/test/java/com/annimon/ownlang/parser/LexerBenchmarkTest.java
index 13930e0..fed985b 100644
--- a/src/test/java/com/annimon/ownlang/parser/LexerBenchmarkTest.java
+++ b/src/test/java/com/annimon/ownlang/parser/LexerBenchmarkTest.java
@@ -2,6 +2,7 @@ package com.annimon.ownlang.parser;
 
 import java.io.IOException;
 import java.util.concurrent.TimeUnit;
+import org.junit.Ignore;
 import org.junit.Test;
 import org.openjdk.jmh.annotations.*;
 import org.openjdk.jmh.runner.Runner;
@@ -31,7 +32,8 @@ public class LexerBenchmarkTest {
         }
     }
 
-    //@Test
+    @Ignore
+    @Test
     public void executeBenchmark() throws RunnerException {
         Options opt = new OptionsBuilder()
                 .include(LexerBenchmarkTest.class.getSimpleName())
diff --git a/src/test/java/com/annimon/ownlang/parser/ParserBenchmarkTest.java b/src/test/java/com/annimon/ownlang/parser/ParserBenchmarkTest.java
index fe2528f..c1cba07 100644
--- a/src/test/java/com/annimon/ownlang/parser/ParserBenchmarkTest.java
+++ b/src/test/java/com/annimon/ownlang/parser/ParserBenchmarkTest.java
@@ -3,6 +3,7 @@ package com.annimon.ownlang.parser;
 import java.io.IOException;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
+import org.junit.Ignore;
 import org.junit.Test;
 import org.openjdk.jmh.annotations.*;
 import org.openjdk.jmh.infra.Blackhole;
@@ -33,7 +34,8 @@ public class ParserBenchmarkTest {
         }
     }
 
-    //@Test
+    @Ignore
+    @Test
     public void executeBenchmark() throws RunnerException {
         Options opt = new OptionsBuilder()
                 .include(ParserBenchmarkTest.class.getSimpleName())