diff --git a/exceptions/stdex.h b/exceptions/stdex.h
index 676cb1e..04b864c 100644
--- a/exceptions/stdex.h
+++ b/exceptions/stdex.h
@@ -3,7 +3,7 @@
 
 #include "../oop.h"
 
-#define Exception construct(Exception)
+//#define Exception construct(Exception)
 extern class(Exception, Object_class, NO_INTERFACES, true) {
 	extends(Object_t);	
 
@@ -15,7 +15,7 @@ extern class(Exception, Object_class, NO_INTERFACES, true) {
 void method(Exception, populate)(Exception_t*, class_t);
 Exception_t* method(Exception, construct)(const char*);
 
-#define NullPointerException construct(NullPointerException)
+//#define NullPointerException construct(NullPointerException)
 extern class(NullPointerException, Exception_class, NO_INTERFACES, true) {
 	extends(Exception_t);
 
@@ -25,7 +25,7 @@ extern class(NullPointerException, Exception_class, NO_INTERFACES, true) {
 void method(NullPointerException, populate)(NullPointerException_t*, class_t);
 NullPointerException_t* method(NullPointerException, construct)(void);
 
-#define OutOfMemoryException construct(OutOfMemoryException)
+//#define OutOfMemoryException construct(OutOfMemoryException)
 extern class(OutOfMemoryException, Exception_class, NO_INTERFACES, true) {
 	extends(Exception_t);
 
@@ -35,7 +35,7 @@ extern class(OutOfMemoryException, Exception_class, NO_INTERFACES, true) {
 void method(OutOfMemoryException, populate)(OutOfMemoryException_t*, class_t);
 OutOfMemoryException_t* method(OutOfMemoryException, construct)(void);
 
-#define IndexOutOfBoundsException construct(IndexOutOfBoundsException)
+//#define IndexOutOfBoundsException construct(IndexOutOfBoundsException)
 extern class(IndexOutOfBoundsException, Exception_class, NO_INTERFACES, true) {
 	extends(Exception_t);
 
@@ -45,7 +45,7 @@ extern class(IndexOutOfBoundsException, Exception_class, NO_INTERFACES, true) {
 void method(IndexOutOfBoundsException, populate)(IndexOutOfBoundsException_t*, class_t);
 IndexOutOfBoundsException_t* method(IndexOutOfBoundsException, construct)(size_t, size_t);
 
-#define IllegalArgumentException construct(IllegalArgumentException)
+//#define IllegalArgumentException construct(IllegalArgumentException)
 extern class(IllegalArgumentException, Exception_class, NO_INTERFACES, true) {
 	extends(Exception_t);
 
@@ -55,7 +55,7 @@ extern class(IllegalArgumentException, Exception_class, NO_INTERFACES, true) {
 void method(IllegalArgumentException, populate)(IllegalArgumentException_t*, class_t);
 IllegalArgumentException_t* method(IllegalArgumentException, construct)(const char*);
 
-#define ClassNotInstanceableException construct(ClassNotInstanceableException)
+//#define ClassNotInstanceableException construct(ClassNotInstanceableException)
 extern class(ClassNotInstanceableException, Exception_class, NO_INTERFACES, true) {
 	extends(Exception_t);
 
diff --git a/lists/arraylist.c b/lists/arraylist.c
index b201efe..af2c2c1 100644
--- a/lists/arraylist.c
+++ b/lists/arraylist.c
@@ -30,7 +30,7 @@ size_t method(ArrayList, length)(void* this) {
 void method(ArrayList, add)(void* this, void* obj) {	
 	throws(NullPointerException_t, OutOfMemoryException_t);
 	if (this == NULL)
-		throw(new NullPointerException());
+		throw(new (NullPointerException)());
 	
 	to_list(list, this);
 
@@ -46,12 +46,12 @@ void method(ArrayList, add)(void* this, void* obj) {
 void* method(ArrayList, get)(void* this, size_t index) {
 	throws(NullPointerException_t, IndexOutOfBoundsException_t);
 	if (this == NULL)
-		throwr(new NullPointerException(), NULL);
+		throwr(new (NullPointerException)(), NULL);
 	
 	to_list(list, this);
 
 	if (index >= list->currentSize)
-		throwr(new IndexOutOfBoundsException(index, list->currentSize), NULL);
+		throwr(new (IndexOutOfBoundsException)(index, list->currentSize), NULL);
 
 	return list->data[index];
 
@@ -59,12 +59,12 @@ void* method(ArrayList, get)(void* this, size_t index) {
 void method(ArrayList, remove)(void* this, size_t index) {
 	throws(NullPointerException_t, OutOfMemoryException_t);
 	if (this == NULL)
-		throw(new NullPointerException());
+		throw(new (NullPointerException)());
 	
 	to_list(list, this);
 
 	if (index >= list->currentSize)
-		throw(new IndexOutOfBoundsException(index, list->currentSize));
+		throw(new (IndexOutOfBoundsException)(index, list->currentSize));
 
 	for(size_t i = index; i < list->currentSize - 1; i++) {
 		list->data[i] = list->data[i + 1];
@@ -78,7 +78,7 @@ void method(ArrayList, remove)(void* this, size_t index) {
 void method(ArrayList, push)(void* this, void* obj) {
 	throws(NullPointerException_t);
 	if (this == NULL)
-		throw(new NullPointerException());
+		throw(new (NullPointerException)());
 	
 	to_list(list, this);
 
@@ -88,7 +88,7 @@ void method(ArrayList, push)(void* this, void* obj) {
 void* method(ArrayList, pop)(void* this) {
 	throws(NullPointerException_t, OutOfMemoryException_t);
 	if (this == NULL)
-		throwr(new NullPointerException(), NULL);
+		throwr(new (NullPointerException)(), NULL);
 	
 	to_list(list, this);
 
@@ -99,12 +99,59 @@ void* method(ArrayList, pop)(void* this) {
 	return element;
 }
 
+void* method(ArrayList, clone)(void* this) {
+	throws(NullPointerException_t, OutOfMemoryException_t);
+	if (this == NULL)
+		throwr(new (NullPointerException)(), NULL);
+
+	to_list(list, this);
+
+	ArrayList_t* listn = new (ArrayList)();
+
+	listn->currentSize = list->currentSize;
+	listn->steps = list->steps;
+	listn->sizeStep = list->sizeStep;
+
+	sr_(listn->data = clone(list->data, list->currentSize), NULL);
+
+	return (void*) listn;
+}
+
+int method(ArrayList, compare)(void* this, void* other) {
+	throws(NullPointerException_t);
+	if (this == NULL)
+		throwr(new (NullPointerException)(), -1);
+
+	if (other == NULL)
+		throwr(new (NullPointerException)(), -1);	
+
+	to_list(list, this);
+
+	Object_t* obj = (Object_t*) other;
+	if (oop_get_class_from_obj(obj).id != oop_get_class_from_obj((Object_t*) list).id)
+		throwr(new (IllegalArgumentException)("Compared objects are not instances of the same class."), -1);
+
+	to_list(olist, obj);
+
+	if (list->currentSize == olist->currentSize)
+		return 0;
+	else if (list->currentSize > olist->currentSize)
+		return 1;
+	else
+		return -1;
+}
+
 void method(ArrayList, destruct)(ArrayList_t* this) {
 	throws(NullPointerException_t);
 	if (this == NULL)
-		throw(new NullPointerException());
-	
+		throw(new (NullPointerException)());
 	
+	to_list(list, this);
+
+	if (list->data != NULL)
+		free(list->data);
+
+	list->super.destruct((Object_t*) list);
 }
 
 void method(ArrayList, populate)(ArrayList_t* obj, class_t c) {
@@ -115,6 +162,8 @@ void method(ArrayList, populate)(ArrayList_t* obj, class_t c) {
 	obj->steps = 0;
 	obj->sizeStep = DEFAULT_SIZE_STEP;
 
+	add_hashcode(obj);
+
 	add_method(obj, ArrayList, destruct);
 	add_method(obj, ArrayList, length);
 	add_method(obj, ArrayList, add);
diff --git a/lists/arraylist.h b/lists/arraylist.h
index 4921bcd..cf6d56d 100644
--- a/lists/arraylist.h
+++ b/lists/arraylist.h
@@ -4,13 +4,16 @@
 #include "../oop.h"
 #include "lists.h"
 
-#define ArrayList construct(ArrayList)
-extern class(ArrayList, Object_class, (interfaces){4 namely {Cloneable_class and List_class and Countable_class and Stack_class}}, true) {
+// #define ArrayList construct(ArrayList)
+extern class(ArrayList, Object_class, (interfaces){5 namely {Cloneable_class and List_class and Countable_class and Stack_class and Compareable_class}}, true) {
 	extends(Object_t);
 	implements(Cloneable);
 	implements(List);
 	implements(Countable);
 	implements(Stack);
+	implements(Compareable);
+	def_hashcode();
+
 	void (*destruct)(defclass ArrayList*);
 
 	size_t currentSize;
diff --git a/lists/lists.h b/lists/lists.h
index 20f79a0..35f7b9a 100644
--- a/lists/lists.h
+++ b/lists/lists.h
@@ -18,6 +18,12 @@ extern interface(Stack)
 #define Stack_interface void (*push)(void*, void*); void* (*pop)(void*);
 #define Stack(...) NULL; _Pragma("GCC error \"Cannot make instance of interface Stack.\"");
 
+/*typedef Object_t Set_t;
+extern interface(Set)
+#define Set_interface void (*add)(void*, void*); void (*remove)(void*, void*); void* (*contains)(void*, void*);
+#define Set(...) NULL; _Pragma("GCC error \"Cannot make instance of interface Set.\"");
+*/
+
 typedef struct iterator_args {
 	void* list;
 	void* parameter;
diff --git a/memory.c b/memory.c
index ae91017..7b14e62 100644
--- a/memory.c
+++ b/memory.c
@@ -8,13 +8,13 @@
 void allocate_sub(size_t size, void** ptr) { throws(OutOfMemoryException_t);
 	*ptr = malloc(size);
 	if (*ptr == NULL) {
-		throw(new OutOfMemoryException());
+		throw(new (OutOfMemoryException)());
 	}
 }
 
 void* allocate_o(class_t c, size_t size) { throws(OutOfMemoryException_t, ClassNotInstanceableException_t);
 	if (!oop_is_instanceable(c))
-		throwr(new ClassNotInstanceableException(oop_get_class_name(c)), NULL);
+		throwr(new (ClassNotInstanceableException)(oop_get_class_name(c)), NULL);
 	void* ptr;
 	sr_(allocate_sub(size, &ptr), NULL);
 	return ptr;
@@ -29,7 +29,7 @@ void* allocate(size_t size) { throws(OutOfMemoryException_t);
 void reallocate_sub(size_t size, void** ptr, void* old) { throws(OutOfMemoryException_t);
 	*ptr = realloc(old, size);
 	if (*ptr == NULL) {
-		throw(new OutOfMemoryException());
+		throw(new (OutOfMemoryException)());
 	}
 }
 
diff --git a/oop.c b/oop.c
index 6940560..86b0eb1 100644
--- a/oop.c
+++ b/oop.c
@@ -2,6 +2,7 @@
 #include "memory.h"
 #include "try.h"
 #include "exceptions/stdex.h"
+#include "misc.h"
 
 #include <string.h>
 #include <stdlib.h>
@@ -98,7 +99,7 @@ void oop_check_interface(class_t c, Object_t* obj) {
 	throws(IllegalArgumentException_t);
 
 	if (!instanceof(obj, c))
-		throw(new IllegalArgumentException("Object is not instance of interface."));
+		throw(new (IllegalArgumentException)("Object is not instance of interface."));
 }
 
 
@@ -120,7 +121,17 @@ Object_t* method(Object, construct)() { throws(OutOfMemoryException_t);
 	return obj;
 }
 
+int method(Object, hashCode)(Object_t* obj) {
+	UNUSED(obj);
+	return 0;
+}
+
 void method(Object, populate)(Object_t* obj, class_t type) {
 	obj->meta_obj.type = type;
 	add_method(obj, Object, destruct);
 }
+
+
+int method(DefMethods, hashCode)(void* obj) {
+	return ((Object_t*) obj)->hashCode(obj);
+}
diff --git a/oop.h b/oop.h
index e06fec6..735e0be 100644
--- a/oop.h
+++ b/oop.h
@@ -8,7 +8,8 @@
 #define interface(name) class_t name##_class; __attribute__ ((constructor)) static void add_##name##_interface(void) { name##_class.id = oop_add_class(#name, true, NO_SUPER_CLASS, NO_INTERFACES, false);}
 #define class(name, superclass, interfaces, instanceable) class_t name##_class; __attribute__ ((constructor)) static void add_##name##_class(void) { name##_class.id = oop_add_class(#name, false, superclass, interfaces, instanceable);} typedef struct name
 #define method(class, method) class ##_method_## method
-#define add_method(object, class, method) object->method = class ##_method_## method
+#define add_method(object, class, method) override_method(object, class, class, method)
+#define override_method(object, class, mclass, method) ((class ## _t*) object)->method = mclass ##_method_## method
 
 #define implements(i) i##_interface
 #define extends(type) type super
@@ -19,7 +20,7 @@
 #define instanceof(obj, class) oop_instance_of(obj, class)
 
 #define call(obj, method) (obj)->method((obj))
-#define new
+#define new(class) construct(class)
 #define defclass	struct
 
 #define MAX_CLASSES 1024
@@ -58,10 +59,11 @@ typedef struct meta_object {
 
 class_id_t oop_add_class(const char*, bool, class_t, iflist_t, bool);
 
-#define Object construct(Object)
+//#define Object construct(Object)
 extern class(Object, NO_SUPER_CLASS, NO_INTERFACES, false) {
 	meta_object_t meta_obj;
 	void (*destruct)(defclass Object*);
+	int (*hashCode)(void*);
 } Object_t;
 
 extern interface(Cloneable)
@@ -72,6 +74,10 @@ extern interface(Compareable)
 #define Compareable_interface int(*compare)(void*)
 #define Compareable(...) NULL; _Pragma("GCC error \"Cannot make instance of interface Compareable.\"");
 
+#define def_hashcode() int(*hashCode)(void*)
+#define add_hashcode(obj) obj->hashCode = DefMethods_method_hashCode
+int method(DefMethods, hashCode)(void*);
+
 bool oop_instance_of_id(void*, class_id_t);
 bool oop_instance_of(void*, class_t);
 const char* oop_get_class_name(class_t);
@@ -84,6 +90,6 @@ class_t oop_get_class_from_obj(Object_t*);
 void oop_check_interface(class_t, Object_t*);
 
 Object_t* method(Object, construct)(void);
-void method(Object, populate)(Object_t* obj, class_t);
+void method(Object, populate)(Object_t*, class_t);
 
 #endif
diff --git a/tools/strbuilder.c b/tools/strbuilder.c
index 7333d9b..3f1fd27 100644
--- a/tools/strbuilder.c
+++ b/tools/strbuilder.c
@@ -12,7 +12,7 @@ void method(Strbuilder, clear)(Strbuilder_t* this) {
 	throws(NullPointerException_t);
 
 	if (this == NULL)
-		throw(new NullPointerException());
+		throw(new (NullPointerException)());
 
 	for (int i = 0; i < this->nrstrings; i++) {
 		free(this->strings[i]);
@@ -26,7 +26,7 @@ void method(Strbuilder, destruct)(Strbuilder_t* this) {
 	throws(NullPointerException_t);
 
 	if (this == NULL)
-		throw(new NullPointerException());
+		throw(new (NullPointerException)());
 
 	this->clear(this);
 	this->super.destruct((Object_t*) this);
@@ -36,7 +36,7 @@ void method(Strbuilder, add)(Strbuilder_t* this, const char* string) {
 	throws(OutOfMemoryException_t, NullPointerException_t);
 
 	if (this == NULL || string == NULL)
-		throw(new NullPointerException());
+		throw(new (NullPointerException)());
 
 	s_(this->strings = reallocate(this->strings, ++this->nrstrings * sizeof(char*)));
 	s_(this->strings[this->nrstrings - 1] = allocate(strlen(string) + 1));
@@ -47,7 +47,7 @@ size_t method(Strbuilder, length)(Strbuilder_t* this) {
 	throws(NullPointerException_t);
 
 	if (this == NULL)
-		throwr(new NullPointerException(), 0);
+		throwr(new (NullPointerException)(), 0);
 
 	size_t length = 0;
 	if (this->string != NULL)
@@ -62,7 +62,7 @@ void method(Strbuilder, build)(Strbuilder_t* this) {
 	throws(OutOfMemoryException_t, NullPointerException_t);
 
 	if (this == NULL)
-		throw(new NullPointerException());
+		throw(new (NullPointerException)());
 
 	size_t length = this->length(this);
 	bool empty = this->string == NULL;
@@ -80,7 +80,7 @@ const char* method(Strbuilder, get)(Strbuilder_t* this) {
 	throws(NullPointerException_t);
 
 	if (this == NULL)
-		throwr(new NullPointerException(), NULL);
+		throwr(new (NullPointerException)(), NULL);
 
 	if (this->string == NULL)
 		return "";
@@ -88,6 +88,7 @@ const char* method(Strbuilder, get)(Strbuilder_t* this) {
 	return this->string;
 }
 
+
 Strbuilder_t* method(Strbuilder, construct)(const char* string) { 
 	throws(OutOfMemoryException_t);
 
@@ -103,6 +104,18 @@ Strbuilder_t* method(Strbuilder, construct)(const char* string) {
 	return obj;
 }
 
+int method(Strbuilder, hashCode)(void* obj) {
+	throws(NullPointerException_t);
+	if (obj == NULL)
+		throwr(new (NullPointerException)(), 0);
+
+	Strbuilder_t* builder = (Strbuilder_t*) obj;
+	
+
+	UNUSED(builder);
+	
+	return 0;
+}
 
 void method(Strbuilder, populate)(Strbuilder_t* obj, class_t c) {
 	populate(Object)((Object_t*) obj, c);
@@ -111,6 +124,9 @@ void method(Strbuilder, populate)(Strbuilder_t* obj, class_t c) {
 	obj->strings = NULL;
 	obj->nrstrings = 0;
 
+	add_hashcode(obj);
+	override_method(obj, Object, Strbuilder, hashCode);
+
 	add_method(obj, Strbuilder, destruct);
 	add_method(obj, Strbuilder, add);
 	add_method(obj, Strbuilder, build);
diff --git a/tools/strbuilder.h b/tools/strbuilder.h
index d3a8d74..56f6df4 100644
--- a/tools/strbuilder.h
+++ b/tools/strbuilder.h
@@ -4,9 +4,10 @@
 #include <stdlib.h>
 #include "../oop.h"
 
-#define Strbuilder construct(Strbuilder)
+//#define Strbuilder construct(Strbuilder)
 extern class(Strbuilder, Object_class, NO_INTERFACES, true) {
 	extends(Object_t);
+	def_hashcode();
 
 	char* string;
 	char** strings;
diff --git a/try.c b/try.c
index 641d246..5739c0b 100644
--- a/try.c
+++ b/try.c
@@ -109,7 +109,7 @@ void try_throw(try_t id, void* exception) {
 				e->msg);
 		#endif
 
-		e->destruct(); // destruct of exception (not sub classes), because we don't know what this is
+		e->destruct(e); // destruct of exception (not sub classes), because we don't know what this is
 
 		_print_backtrace(stderr, 2);
 	} else {