Make LinkedList a lot better

luna/include/luna/LinkedList.h

@@ -12,10 +12,31 @@ template <typename T> class DoublyLinkedList;
 
 template <typename T> class DoublyLinkedListNode
 {
+    using SelfType = DoublyLinkedListNode<T>;
 
   private:
-    DoublyLinkedListNode<T>* m_next_node;
-    DoublyLinkedListNode<T>* m_last_node;
+    SelfType* m_next_node;
+    SelfType* m_last_node;
+
+    void set_next(SelfType* next)
+    {
+        m_next_node = next;
+    }
+
+    void set_last(SelfType* last)
+    {
+        m_last_node = last;
+    }
+
+    SelfType* get_next()
+    {
+        return m_next_node;
+    }
+
+    SelfType* get_last()
+    {
+        return m_last_node;
+    }
 
     void detach_from_list()
     {
@@ -23,7 +44,7 @@ template <typename T> class DoublyLinkedListNode
         m_last_node->m_next_node = m_next_node;
     }
 
-    void add_to_list(DoublyLinkedListNode<T>* end_node)
+    void add_to_list(SelfType* end_node)
     {
         end_node->m_next_node = this;
         this->m_last_node = end_node;
@@ -34,14 +55,19 @@ template <typename T> class DoublyLinkedListNode
 
 template <typename T> class DoublyLinkedList
 {
+    using Node = DoublyLinkedListNode<T>;
+
   public:
     void append(T* ptr)
     {
-        DoublyLinkedListNode<T>* node = (DoublyLinkedListNode<T>*)ptr;
+        Node* const node = extract_node(ptr);
         if (!m_start_node) m_start_node = node;
         if (m_end_node) node->add_to_list(m_end_node);
         else
-            node->m_next_node = node->m_last_node = nullptr;
+        {
+            node->set_next(nullptr);
+            node->set_last(nullptr);
+        }
         m_end_node = node;
 
         m_count++;
@@ -49,24 +75,24 @@ template <typename T> class DoublyLinkedList
 
     void append_after(T* base, T* ptr)
     {
-        DoublyLinkedListNode<T>* new_node = (DoublyLinkedListNode<T>*)ptr;
-        DoublyLinkedListNode<T>* base_node = (DoublyLinkedListNode<T>*)base;
+        Node* const new_node = extract_node(ptr);
+        Node* const base_node = extract_node(base);
 
         if (m_end_node == base_node) m_end_node = new_node;
 
-        new_node->m_next_node = base_node->m_next_node;
-        base_node->m_next_node = new_node;
-        new_node->m_last_node = base_node;
+        new_node->set_next(base_node->get_next());
+        base_node->set_next(new_node);
+        new_node->set_last(base_node);
 
         m_count++;
     }
 
     T* remove(T* ptr)
     {
-        DoublyLinkedListNode<T>* node = (DoublyLinkedListNode<T>*)ptr;
+        Node* const node = extract_node(ptr);
 
-        if (node == m_end_node) m_end_node = node->m_last_node;
-        if (node == m_start_node) m_start_node = node->m_next_node;
+        if (node == m_end_node) m_end_node = node->get_last();
+        if (node == m_start_node) m_start_node = node->get_next();
 
         node->detach_from_list();
 
@@ -87,40 +113,32 @@ template <typename T> class DoublyLinkedList
 
     Result<T*> next(T* item)
     {
-        return nonnull_or_error((T*)((DoublyLinkedListNode<T>*)item)->m_next_node);
+        return nonnull_or_error((T*)extract_node(item)->get_next());
     }
 
     Result<T*> previous(T* item)
     {
-        return nonnull_or_error((T*)((DoublyLinkedListNode<T>*)item)->m_last_node);
+        return nonnull_or_error((T*)extract_node(item)->get_last());
     }
 
     template <typename Callback> void for_each(Callback callback)
     {
-        for (DoublyLinkedListNode<T>* node = m_start_node; node; node = node->m_next_node) { callback((T*)node); }
+        for (Node* node = m_start_node; node; node = node->get_next()) { callback((T*)node); }
     }
 
     template <typename Callback> void for_each_reversed(Callback callback)
     {
-        for (DoublyLinkedListNode<T>* node = m_end_node; node; node = node->m_last_node) { callback((T*)node); }
+        for (Node* node = m_end_node; node; node = node->get_last()) { callback((T*)node); }
     }
 
     template <typename Callback> void for_each_after(T* start, Callback callback)
     {
-        for (DoublyLinkedListNode<T>* node = ((DoublyLinkedListNode<T>*)start)->m_next_node; node;
-             node = node->m_next_node)
-        {
-            callback((T*)node);
-        }
+        for (Node* node = extract_node(start)->m_next_node; node; node = node->get_next()) { callback((T*)node); }
     }
 
     template <typename Callback> void for_each_before(T* end, Callback callback)
     {
-        for (DoublyLinkedListNode<T>* node = ((DoublyLinkedListNode<T>*)end)->m_last_node; node;
-             node = node->m_last_node)
-        {
-            callback((T*)node);
-        }
+        for (Node* node = extract_node(end)->m_last_node; node; node = node->get_last()) { callback((T*)node); }
     }
 
     usize count()
@@ -129,8 +147,13 @@ template <typename T> class DoublyLinkedList
     }
 
   private:
-    DoublyLinkedListNode<T>* m_start_node = nullptr;
-    DoublyLinkedListNode<T>* m_end_node = nullptr;
+    Node* m_start_node = nullptr;
+    Node* m_end_node = nullptr;
+
+    Node* extract_node(T* item)
+    {
+        return (Node*)item;
+    }
 
     usize m_count = 0;
 };