diff --git a/include/console.h b/include/console.h
index 199a5c6..5445dfa 100644
--- a/include/console.h
+++ b/include/console.h
@@ -75,7 +75,7 @@ void kputs(const char *str);
  * @param format The format string that will be printed in formatted version.
  * @param ... The format parameters that will be used to print the string.
  */
-void kprintf(const char *format, ...);
+void kprintf(const char *format, ...) __attribute__((format(printf,1,2)));
 
 #if defined(__cplusplus)
 }
diff --git a/include/ker/dictionary.hpp b/include/ker/dictionary.hpp
index 5fe2428..c64664c 100644
--- a/include/ker/dictionary.hpp
+++ b/include/ker/dictionary.hpp
@@ -10,7 +10,7 @@ namespace ker
 	{
 	public:
 		typedef Pair<Key, Value> Entry;
-	private:
+    public:
 		Vector<Entry> contents;
 	public:
 		Dictionary() :
@@ -19,6 +19,24 @@ namespace ker
 
 		}
 
+        Dictionary(const Dictionary &other) :
+            contents(other.contents)
+        {
+
+        }
+
+        Dictionary(Dictionary &&other) :
+            contents(other.contents)
+        {
+            other.contents = Vector<Entry>();
+        }
+
+        Dictionary & operator = (const Dictionary &other)
+        {
+            this->contents = other.contents;
+            return *this;
+        }
+
 		Value &at(const Key &key)
 		{
 			for(auto &&pair : this->contents)
@@ -39,6 +57,15 @@ namespace ker
 			}
 		}
 
+        Value get(const Key &key) const
+        {
+            if(this->contains(key)) {
+                return this->at(key);
+            } else {
+                return Value();
+            }
+        }
+
 		bool contains(const Key &key) const
         {
 			for(const auto &pair : this->contents)
diff --git a/include/ker/pair.hpp b/include/ker/pair.hpp
index 369d493..250d96a 100644
--- a/include/ker/pair.hpp
+++ b/include/ker/pair.hpp
@@ -16,5 +16,27 @@ namespace ker
 		{
 
 		}
+
+        Pair(const Pair &other) :
+            first(other.first),
+            second(other.second)
+        {
+
+        }
+
+        Pair(Pair &&other) :
+            first(other.first),
+            second(other.second)
+        {
+            other.first = First();
+            other.second = Second();
+        }
+
+        Pair & operator = (const Pair &other)
+        {
+            this->first = other.first;
+            this->second = other.second;
+            return *this;
+        }
 	};
 }
diff --git a/include/ker/string.hpp b/include/ker/string.hpp
index 3b031c9..9674829 100644
--- a/include/ker/string.hpp
+++ b/include/ker/string.hpp
@@ -34,29 +34,22 @@ namespace ker
 
         String & operator = (const String &other)
         {
-            free(this->mText);
-            this->mLength = other.mLength;
-
-            this->mText = (uint8_t*)malloc(this->mLength + 1);
-            memcpy(this->mText, other.mText, this->mLength + 1);
+            this->copyFrom(other.mText, other.mLength);
+            return *this;
         }
 
 		String(const char *text) :
 			mText(nullptr),
 			mLength(0)
         {
-            this->mLength = strlen(text);
-            this->mText = (uint8_t*)malloc(this->mLength + 1);
-            memcpy(this->mText, text, this->mLength);
-            this->mText[this->mLength] = 0;
+            this->copyFrom(reinterpret_cast<const uint8_t*>(text), strlen(text));
 		}
 
 		String(const uint8_t *bytes, size_t length) :
-            mText((uint8_t*)malloc(length + 1)),
+            mText(nullptr),
 			mLength(length)
 		{
-            memcpy(this->mText, bytes, length);
-            this->mText[this->mLength] = 0; // last byte is always 0
+            this->copyFrom(bytes, length);
 		}
 
 		~String()
@@ -76,7 +69,7 @@ namespace ker
 			if(this->mLength != other.mLength) {
 				return false;
 			}
-			return memcmp(this->mText, other.mText, this->mLength) != 0;
+            return memcmp(this->mText, other.mText, this->mLength) == 0;
 		}
 
 		const uint8_t *text() const
@@ -123,5 +116,16 @@ namespace ker
 		{
 			return !this->equals(other);
 		}
+    private:
+        void copyFrom(const uint8_t *bytes, size_t length)
+        {
+            if(this->mText != nullptr) {
+                free(this->mText);
+            }
+            this->mText = (uint8_t*)malloc(length + 1);
+            memcpy(this->mText, bytes, length);
+            this->mLength = length;
+            this->mText[this->mLength] = 0; // last byte is always 0
+        }
 	};
 };
diff --git a/include/ker/vector.hpp b/include/ker/vector.hpp
index 6dc11c1..25b9742 100644
--- a/include/ker/vector.hpp
+++ b/include/ker/vector.hpp
@@ -23,12 +23,53 @@ namespace ker
 			this->reserve(Vector<T>::initialCap);
 		}
 
+        Vector(const Vector &other) :
+            mData(nullptr),
+            mLength(0),
+            mReserved(0)
+        {
+            this->mLength = other.mLength;
+            if(this->mLength > 0) {
+                this->reserve(this->mLength);
+                for(size_t i = 0; i < this->mLength; i++) {
+                    new (&this->mData[i]) T(other.mData[i]);
+                }
+            }
+        }
+
+        Vector(Vector &&other) :
+            mData(other.mData),
+            mLength(other.mLength),
+            mReserved(other.mReserved)
+        {
+            other.mData = nullptr;
+            other.mLength = 0;
+            other.mReserved = 0;
+        }
+
+        Vector & operator = (const Vector &other)
+        {
+            this->resize(other.mLength);
+            for(size_t i = 0; i < this->mLength; i++)
+            {
+                this->mData[i] = other.mData[i];
+            }
+            return *this;
+        }
+
 		explicit Vector(size_t initialReserve) :
 			Vector()
 		{
 			this->reserve(initialReserve);
 		}
 
+        ~Vector()
+        {
+            if(this->mData != nullptr) {
+                free(this->mData);
+            }
+        }
+
 		size_t length() const
 		{
 			return this->mLength;
@@ -47,7 +88,7 @@ namespace ker
 		void append(const T &value)
 		{
 			this->reserve(this->mLength + 1);
-			new (&this->mData[this->mLength - 1]) T(value);
+            new (&this->mData[this->mLength]) T(value);
 			this->mLength += 1;
 		}
 
@@ -67,6 +108,7 @@ namespace ker
 					new (&this->mData[i]) T ();
 				}
 			}
+            this->mLength = size;
 		}
 
 		void reserve(size_t space)
@@ -82,6 +124,7 @@ namespace ker
 				free(this->mData);
 			}
 			this->mData = newData;
+            this->mReserved = space;
 		}
 
 		T& operator [](size_t idx)
diff --git a/src/console.c b/src/console.c
index bb5cb4e..a82dda3 100644
--- a/src/console.c
+++ b/src/console.c
@@ -219,4 +219,4 @@ void kprintf(const char *format, ...)
 		}
 	}
 	va_end(vl);
-}
\ No newline at end of file
+}
diff --git a/src/vm.cpp b/src/vm.cpp
index a1d4f07..19f5883 100644
--- a/src/vm.cpp
+++ b/src/vm.cpp
@@ -10,17 +10,120 @@ extern "C" {
 //    extern size_t file01_size;
 }
 
-char file01[] = "VAR global : INT;\0";
+char file01[] = R"code(
+VAR global : INT;
+PUB main() | i : INT
+BEGIN
+    print(10, 20, 30);
+    0 -> i;
+    REPEAT
+    BEGIN
+        print(i);
+        i + 1 -> i;
+    END
+END)code";
+
+void cpp_test();
+
+class PrintMethod :
+        public Method
+{
+public:
+    Variable invoke(Vector<Variable> arguments) override;
+};
+
+Variable PrintMethod::invoke(Vector<Variable> arguments)
+{
+    for(auto &var : arguments)
+    {
+        var.printval();
+        kprintf(" ");
+    }
+    kprintf("\n");
+    return Variable::Void;
+}
+
+extern "C" void vm_start()
+{
+    // cpp_test();
+
+    kprintf("Parse kernel module: ");
+    Module *module = VM::load(file01, sizeof(file01) - 1);
+    if(module == nullptr) {
+        kprintf("Could not load module :(\n");
+        return;
+    }
+
+    kprintf("Module successfully loaded :)\n");
+
+    module->methods.add("print", new PrintMethod());
+
+    for(const auto &var : module->variables)
+    {
+        kprintf("Variable: '%s' => '", var.first.str());
+        var.second->printval();
+        kprintf("'\n");
+    }
+
+    for(const auto &fn : module->methods)
+    {
+        kprintf("Function: '%s'\n", fn.first.str());
+    }
+
+    Method *main = module->method("main");
+    if(main == nullptr) {
+        kprintf("Script has no main method.\n");
+        return;
+    }
+
+    main->invoke({ });
+
+    delete module;
+}
+
 
 String fn()
 {
     return String("keks");
 }
 
-extern "C" void vm_start()
+void put(Vector<int> &v)
+{
+    kprintf("v[%d]: ", v.length());
+    for(int i : v) { kprintf("%d,", i); }
+    kprintf("\n");
+}
+
+void put(Vector<String> &v)
+{
+    kprintf("v[%d]: ", v.length());
+    for(String &s : v) { kprintf("[%s],", s.str()); }
+    kprintf("\n");
+}
+
+void put(Dictionary<int, int> &d)
+{
+    kprintf("dict: ");
+    for(auto &it : d)
+    {
+        kprintf("[%d -> %d] ", it.first, it.second);
+    }
+    kprintf("\n");
+}
+
+void put(Dictionary<String, String> &d)
+{
+    kprintf("dict: ");
+    for(auto &it : d)
+    {
+        kprintf("[%s -> %s] ", it.first.str(), it.second.str());
+    }
+    kprintf("\n");
+}
+
+void cpp_test()
 {
     kprintf("Testing ker::String:\n");
-
     {
         String a("hello");
         String b(a);
@@ -33,20 +136,89 @@ extern "C" void vm_start()
         kprintf("'%s' '%s' '%s' '%s' '%s'\n", a.str(), b.str(), c.str(), d.str(), e.str());
     }
 
+    kprintf("Testing ker::Pair:\n");
+    {
+        Pair<int, int> a(10, 20);
+        Pair<String, String> b("Hey", "Affe");
 
-    kprintf("Parse kernel module:");
-    Module *module = VM::load(file01, sizeof(file01));
-    if(module == nullptr) {
-        kprintf("Could not load module :(\n");
-        return;
+        Pair<int, int> c(a);
+        Pair<String, String> d(b);
+
+        Pair<int, int> e; e = a;
+        Pair<String, String> f; f = b;
+
+        kprintf("'%d,%d' '%d,%d' '%d,%d'\n", a.first, a.second, c.first, c.second, e.first, e.second);
+        kprintf("'%s,%s' '%s,%s' '%s,%s'\n", b.first.str(), b.second.str(), d.first.str(), d.second.str(), f.first.str(), f.second.str());
     }
 
-    kprintf("Module successfully loaded :)\n");
-
-    for(const auto &var : module->variables)
+    kprintf("Testing ker::Vector:\n");
     {
-        kprintf("Variable: '%s' => '");
-        var.second->printval();
-        kprintf("\n");
+        Vector<int> a;
+        a.append(1);
+        a.append(2);
+        a.append(3);
+
+        Vector<int> c;
+        Vector<int> b(a);
+        c = a;
+
+        put(a);
+        put(b);
+        put(c);
+    }
+    {
+        Vector<String> a;
+        a.append("x");
+        a.append("y");
+        a.append("z");
+
+        Vector<String> c;
+        Vector<String> b(a);
+        c = a;
+
+        put(a);
+        put(b);
+        put(c);
+    }
+
+    kprintf("Testing ker::Dictionary:\n");
+    {
+        kprintf("int -> int\n");
+        Dictionary<int, int> a;
+        a.add(1, 30);
+        a.add(2, 20);
+        a.add(3, 10);
+
+        kprintf("%d %d\n", a.contains(1), a.contains(4));
+        kprintf("%d %d\n", a.at(1), a.at(3));
+        kprintf("%d %d\n", a[1], a[3]);
+
+        Dictionary<int, int> b(a);
+        Dictionary<int, int> c;
+        c = a;
+
+        put(a);
+        put(b);
+        put(c);
+    }
+
+    {
+        kprintf("String -> String\n");
+        Dictionary<String, String> a;
+        a.add("x", "30");
+        a.add("y", "20");
+        a.add("z", "10");
+
+        kprintf("%d %d\n", a.contains("x"), a.contains("w"));
+        kprintf("%s %s\n", a.at("x").str(), a.at("z").str());
+        kprintf("%s %s\n", a["x"].str(), a["z"].str());
+
+        Dictionary<String, String> b(a);
+        Dictionary<String, String> c;
+        c = a;
+
+        put(a);
+        put(b);
+        put(c);
     }
 }
diff --git a/trainscript/trainscript.y b/trainscript/trainscript.y
index 0d006b2..be2370b 100644
--- a/trainscript/trainscript.y
+++ b/trainscript/trainscript.y
@@ -151,7 +151,7 @@ input:
 		using namespace trainscript;
 		auto *mod = context->module;
 
-		Method *method = new Method(mod, $2.body);
+        ScriptMethod *method = new ScriptMethod(mod, $2.body);
 		method->isPublic = $2.header.isPublic;
 		if($2.header.returnValue) {
             method->returnValue = ker::Pair<ker::String, Variable>(
diff --git a/trainscript/tsvm.cpp b/trainscript/tsvm.cpp
index 9c723f8..9974fd1 100644
--- a/trainscript/tsvm.cpp
+++ b/trainscript/tsvm.cpp
@@ -42,9 +42,7 @@ namespace trainscript
 		data.module = module;
 		yylex_init_extra(&data, &data.scanner);
 
-        int error = yyparse(&data);
-        kprintf("[E:%d]", error);
-        bool valid = error == 0;
+        bool valid = yyparse(&data) == 0;
 
 		yylex_destroy(data.scanner);
 		free(internalStorage);
@@ -78,7 +76,7 @@ namespace trainscript
 		}
 	}
 
-	Variable Method::invoke(ker::Vector<Variable> arguments)
+    Variable ScriptMethod::invoke(ker::Vector<Variable> arguments)
 	{
 		LocalContext context(this->module);
 
diff --git a/trainscript/tsvm.hpp b/trainscript/tsvm.hpp
index be627a5..61197b0 100644
--- a/trainscript/tsvm.hpp
+++ b/trainscript/tsvm.hpp
@@ -164,7 +164,15 @@ namespace trainscript
 		}
 	};
 
-	class Method
+    class Method
+    {
+    public:
+        virtual ~Method() { }
+        virtual Variable invoke(ker::Vector<Variable> arguments) = 0;
+    };
+
+    class ScriptMethod :
+            public Method
 	{
 	public:
 		Module *module;
@@ -174,12 +182,12 @@ namespace trainscript
 		ker::Dictionary<ker::String, Variable> locals;
 		ker::Pair<ker::String, Variable> returnValue;
 
-		Method(Module *module, Instruction *block) : module(module), block(block)
+        ScriptMethod(Module *module, Instruction *block) : module(module), block(block)
 		{
 
 		}
 
-		Variable invoke(ker::Vector<Variable> arguments);
+        Variable invoke(ker::Vector<Variable> arguments) override;
 	};
 
 	class Module
@@ -193,12 +201,12 @@ namespace trainscript
 
 		Method *method(const char *name)
 		{
-			return this->methods[name];
+            return this->methods.get(name);
 		}
 
 		Variable *variable(const char *name)
 		{
-			return this->variables[name];
+            return this->variables.get(name);
 		}
 	};