diff --git a/program.own b/program.own
index 10fb83b..4f0656e 100644
--- a/program.own
+++ b/program.own
@@ -91,3 +91,10 @@ print function(map["+"], 4, 5)
 print "\n"
 foreach(map, def(op, func) = echo (4, op, 5, "=", func(4,5)))
 foreach(arr, ::echo)
+
+arr1 = [1,2,3]
+arr1 = arr1 :: 4
+arr2 = [5,6,7]
+print arr1
+print "\n"
+print arr1 << arr2
\ No newline at end of file
diff --git a/src/com/annimon/ownlang/lib/ArrayValue.java b/src/com/annimon/ownlang/lib/ArrayValue.java
index 9a570df..9c96199 100644
--- a/src/com/annimon/ownlang/lib/ArrayValue.java
+++ b/src/com/annimon/ownlang/lib/ArrayValue.java
@@ -9,6 +9,24 @@ import java.util.Iterator;
  */
 public final class ArrayValue implements Value, Iterable<Value> {
     
+    public static ArrayValue add(ArrayValue array, Value value) {
+        final int last = array.elements.length;
+        final ArrayValue result = new ArrayValue(last + 1);
+        System.arraycopy(array.elements, 0, result.elements, 0, last);
+        result.elements[last] = value;
+        return result;
+    }
+    
+    public static ArrayValue merge(ArrayValue array1, ArrayValue array2) {
+        final int length1 = array1.elements.length;
+        final int length2 = array2.elements.length;
+        final int length = length1 + length2;
+        final ArrayValue result = new ArrayValue(length);
+        System.arraycopy(array1.elements, 0, result.elements, 0, length1);
+        System.arraycopy(array2.elements, 0, result.elements, length1, length2);
+        return result;
+    }
+    
     private final Value[] elements;
 
     public ArrayValue(int size) {
diff --git a/src/com/annimon/ownlang/parser/Parser.java b/src/com/annimon/ownlang/parser/Parser.java
index 9fb830b..29e06d0 100644
--- a/src/com/annimon/ownlang/parser/Parser.java
+++ b/src/com/annimon/ownlang/parser/Parser.java
@@ -356,6 +356,10 @@ public final class Parser {
                 result = new BinaryExpression(BinaryExpression.Operator.SUBTRACT, result, multiplicative());
                 continue;
             }
+            if (match(TokenType.COLONCOLON)) {
+                result = new BinaryExpression(BinaryExpression.Operator.PUSH, result, multiplicative());
+                continue;
+            }
             break;
         }
         
diff --git a/src/com/annimon/ownlang/parser/ast/BinaryExpression.java b/src/com/annimon/ownlang/parser/ast/BinaryExpression.java
index 6601197..2e5f8ea 100644
--- a/src/com/annimon/ownlang/parser/ast/BinaryExpression.java
+++ b/src/com/annimon/ownlang/parser/ast/BinaryExpression.java
@@ -17,6 +17,7 @@ public final class BinaryExpression implements Expression {
         MULTIPLY("*"),
         DIVIDE("/"),
         REMAINDER("%"),
+        PUSH("::"),
         // Bitwise
         AND("&"),
         OR("|"),
@@ -50,23 +51,46 @@ public final class BinaryExpression implements Expression {
     public Value eval() {
         final Value value1 = expr1.eval();
         final Value value2 = expr2.eval();
-        if ( (value1 instanceof StringValue) || (value1 instanceof ArrayValue) ) {
-            final String string1 = value1.asString();
-            switch (operation) {
-                case MULTIPLY: {
-                    final int iterations = (int) value2.asNumber();
-                    final StringBuilder buffer = new StringBuilder();
-                    for (int i = 0; i < iterations; i++) {
-                        buffer.append(string1);
-                    }
-                    return new StringValue(buffer.toString());
-                }
-                case ADD:
-                default:
-                    return new StringValue(string1 + value2.asString());
-            }
-        }
         
+        if (value1 instanceof StringValue) {
+            return eval((StringValue) value1, value2);
+        }
+        if (value1 instanceof ArrayValue) {
+            return eval((ArrayValue) value1, value2);
+        }
+        return eval(value1, value2);
+    }
+    
+    private Value eval(StringValue value1, Value value2) {
+        final String string1 = value1.asString();
+        switch (operation) {
+            case MULTIPLY: {
+                final int iterations = (int) value2.asNumber();
+                final StringBuilder buffer = new StringBuilder();
+                for (int i = 0; i < iterations; i++) {
+                    buffer.append(string1);
+                }
+                return new StringValue(buffer.toString());
+            }
+            case ADD:
+            default:
+                return new StringValue(string1 + value2.asString());
+        }
+    }
+    
+    private Value eval(ArrayValue value1, Value value2) {
+        switch (operation) {
+            case LSHIFT:
+                if (!(value2 instanceof ArrayValue))
+                    throw new RuntimeException("Cannot merge non array value to array");
+                return ArrayValue.merge(value1, (ArrayValue) value2);
+            case PUSH: 
+            default:
+                return ArrayValue.add(value1, value2);
+        }
+    }
+    
+    private Value eval(Value value1, Value value2) {
         final double number1 = value1.asNumber();
         final double number2 = value2.asNumber();
         double result;