#include <stdio.h>
#include <demeter.h>

List::List() {
   head = NIL;
   list_length = 0;
}

List::List(char *datum) {
   Node *temp = new Node(datum);

   head = temp;
   list_length = 1;
}

inline Node *List::get_head() {
  return(head);
}

inline Node *List::set_head(Node *new_head) { 
  Node *_old_head = head;
  head = new_head; 
  return(_old_head); 
}

inline int List::get_length() {
  return(list_length);
}

inline int List::set_length(int new_length) {
  int _old_length = list_length;
  list_length = new_length;
  return(_old_length);
}

List *List::cons(char *datum) {
   List *retval = new List;
   Node *temp = new Node(datum);

   temp->set_next(head);
   retval->set_head(temp);
   retval->set_length(list_length + 1);
   return(retval);
}

inline int List::length() {
   return(list_length);
}

int List::traverse() {
   Node *current_node;

   for (current_node = head;
	current_node != NIL;
	current_node = current_node->get_next()) {
      // pretty print current_node->get_datum()
   }
   return(list_length);
}

inline char *List::car() {
   return(head->get_datum());
}

List *List::cdr() {
   List *retval = new List;

   retval->set_head(head->get_next());
   retval->set_length(list_length - 1);
   return(retval);
}

List *List::append(List *second) {
   List *retval = new List;
   Node *last = head, *new_stuff, *temp;

// Replace this by a copy method????

   if (last != NIL) {
      new_stuff = new Node(last->get_datum());
      retval->set_head(new_stuff);
   }   
   while (last->get_next() != NIL) {
      last->set_next(last->get_next());
      temp = new Node(last->get_datum());
      new_stuff->set_next(temp);
      new_stuff = temp;
   }

   last = second->get_head();
   if (last != NIL) {
      temp = new Node(last->get_datum());
      new_stuff->set_next(temp);
      new_stuff = temp;
   }
   while (last->get_next() != NIL) {
      last->set_next(last->get_next());
      temp = new Node(last->get_datum());
      new_stuff->set_next(temp);
      new_stuff = temp;
   }
   retval->set_length(list_length + second->get_length());
   return(retval);
}