# HG changeset patch
# User Eris Caffee <discordia@eldalin.com>
# Date 1293821266 21600
# Node ID c6e3398465272ee47f84333d0bbce91963069804
# Parent  112164f48f30e215795e9c6398d4522cfa85b6b3
Rewrote ll_next and ll_prev to fix bug and implement NULL return when end of list is reached.

diff -r 112164f48f30 -r c6e339846527 src/LinkedList.c
--- a/src/LinkedList.c	Wed Dec 29 02:44:09 2010 -0600
+++ b/src/LinkedList.c	Fri Dec 31 12:47:46 2010 -0600
@@ -236,36 +236,37 @@
 
 
 /*******************************************************************************
- * Select the next element in the list if there is one.
- * Return data pointer of new current element, or NULL is list is empty.
+ * Return NULL if the list is empty or we are already at the tail, otherwise
+ * set Curr to the next element and return its data pointer.
  */
 void * ll_next(LinkedList * this)
    {
    if (!this) return NULL;
    
-   if (this->Curr->next)
+   if (this->Curr && this->Curr->next)
+      {
       this->Curr = this->Curr->next;
-
-   if (this->Curr)
       return this->Curr->data;
+      }
    else
       return NULL;
+
    }
 
 
 /*******************************************************************************
- * Select previous element in the list if there is one.
- * Return data pointer of new current element, or NULL is list is empty.
+ * Return NULL if the list is empty or we are already at the head, otherwise
+ * set Curr to the prev element and return its data pointer.
  */
 void * ll_prev(LinkedList * this)
    {
    if (!this) return NULL;
 
-   if (this->Curr->prev)
+   if (this->Curr && this->Curr->prev)
+      {
       this->Curr = this->Curr->prev;
-
-   if (this->Curr)
       return this->Curr->data;
+      }
    else
       return NULL;
    }
diff -r 112164f48f30 -r c6e339846527 src/main.c
--- a/src/main.c	Wed Dec 29 02:44:09 2010 -0600
+++ b/src/main.c	Fri Dec 31 12:47:46 2010 -0600
@@ -162,10 +162,30 @@
    *p_int = 23;
    ll_push(list3, p_int);
 
-   printf("\n\nlist3: ");
-   for (i=0, size=ll_size(list3); i<size; ++i)
+
+   ll_head(list3);
+   p_int = (int *) ll_data(list3);
+   printf("list3: ");
+   while(p_int)
       {
-      p_int = (int *) ll_pop(list3);
+      printf("%d ", *p_int);
+      p_int = ll_next(list3);
+      }
+   printf("\n");
+   
+   ll_tail(list3);
+   p_int = (int *) ll_data(list3);
+   printf("list3 reversed: ");
+   while(p_int)
+      {
+      printf("%d ", *p_int);
+      p_int = ll_prev(list3);
+      }
+   printf("\n");
+   
+   printf("Clearing list3: ");
+   while (p_int = (int *) ll_pop(list3))
+      {
       printf("%d ", *p_int);
       }
    printf("\n");