Cleaning up and adding comments

Exam/IKT203Exam/Portfolio/SharedLib/TDoublyLinkedList.h

@@ -2,13 +2,16 @@
 #define TDOUBLYLINKEDLIST_H
 #include <string>
 #include <utility>
-#include "SharedLib.h"
-
 
 
+// Doubly linked list used to store document lines.
+// Supports insertion, removal, and indexed access.
+// Chosen because it allows efficient updates in the middle of the document.
 class TDoublyLinkedList {
 
 private:
+    // Internal node storing a single line of text
+    // and links to previous and next nodes.
     struct Node {
         std::string line;
         Node* next;
@@ -45,12 +48,21 @@ private:
 
 public:
     TDoublyLinkedList() : head(nullptr), tail(nullptr), size(0) {}
-    ~TDoublyLinkedList() = default;
+    ~TDoublyLinkedList();
 
     void Append(const std::string &line);
     void Prepend(const std::string& line);
+
+    // Returns pointer to node at given index.
+    // Linear traversal; used internally by Remove and InsertAtIndex.
     [[nodiscard]] Node* NavigateToNode(int index) const;
+
+    // Removes a node at the given index.
+    // Updates links and frees the removed node.
     void Remove(int index);
+
+    // Returns the text stored at the given index.
+    // Uses NavigateToNode internally.
     [[nodiscard]] std::string GetAtIndex(int index) const;
     void InsertAtIndex(int index, const std::string &line);
     [[nodiscard]] int GetSize() const;