1.1 --- a/src/LinkedList.c	Wed Dec 29 02:44:09 2010 -0600
     1.2 +++ b/src/LinkedList.c	Fri Dec 31 12:47:46 2010 -0600
     1.3 @@ -236,36 +236,37 @@
     1.4  
     1.5  
     1.6  /*******************************************************************************
     1.7 - * Select the next element in the list if there is one.
     1.8 - * Return data pointer of new current element, or NULL is list is empty.
     1.9 + * Return NULL if the list is empty or we are already at the tail, otherwise
    1.10 + * set Curr to the next element and return its data pointer.
    1.11   */
    1.12  void * ll_next(LinkedList * this)
    1.13     {
    1.14     if (!this) return NULL;
    1.15     
    1.16 -   if (this->Curr->next)
    1.17 +   if (this->Curr && this->Curr->next)
    1.18 +      {
    1.19        this->Curr = this->Curr->next;
    1.20 -
    1.21 -   if (this->Curr)
    1.22        return this->Curr->data;
    1.23 +      }
    1.24     else
    1.25        return NULL;
    1.26 +
    1.27     }
    1.28  
    1.29  
    1.30  /*******************************************************************************
    1.31 - * Select previous element in the list if there is one.
    1.32 - * Return data pointer of new current element, or NULL is list is empty.
    1.33 + * Return NULL if the list is empty or we are already at the head, otherwise
    1.34 + * set Curr to the prev element and return its data pointer.
    1.35   */
    1.36  void * ll_prev(LinkedList * this)
    1.37     {
    1.38     if (!this) return NULL;
    1.39  
    1.40 -   if (this->Curr->prev)
    1.41 +   if (this->Curr && this->Curr->prev)
    1.42 +      {
    1.43        this->Curr = this->Curr->prev;
    1.44 -
    1.45 -   if (this->Curr)
    1.46        return this->Curr->data;
    1.47 +      }
    1.48     else
    1.49        return NULL;
    1.50     }

     2.1 --- a/src/main.c	Wed Dec 29 02:44:09 2010 -0600
     2.2 +++ b/src/main.c	Fri Dec 31 12:47:46 2010 -0600
     2.3 @@ -162,10 +162,30 @@
     2.4     *p_int = 23;
     2.5     ll_push(list3, p_int);
     2.6  
     2.7 -   printf("\n\nlist3: ");
     2.8 -   for (i=0, size=ll_size(list3); i<size; ++i)
     2.9 +
    2.10 +   ll_head(list3);
    2.11 +   p_int = (int *) ll_data(list3);
    2.12 +   printf("list3: ");
    2.13 +   while(p_int)
    2.14        {
    2.15 -      p_int = (int *) ll_pop(list3);
    2.16 +      printf("%d ", *p_int);
    2.17 +      p_int = ll_next(list3);
    2.18 +      }
    2.19 +   printf("\n");
    2.20 +   
    2.21 +   ll_tail(list3);
    2.22 +   p_int = (int *) ll_data(list3);
    2.23 +   printf("list3 reversed: ");
    2.24 +   while(p_int)
    2.25 +      {
    2.26 +      printf("%d ", *p_int);
    2.27 +      p_int = ll_prev(list3);
    2.28 +      }
    2.29 +   printf("\n");
    2.30 +   
    2.31 +   printf("Clearing list3: ");
    2.32 +   while (p_int = (int *) ll_pop(list3))
    2.33 +      {
    2.34        printf("%d ", *p_int);
    2.35        }
    2.36     printf("\n");