--- stack/stack.c	2002/02/02 15:26:10	1.21
+++ stack/stack.c	2002/02/02 20:49:34	1.26
@@ -64,7 +64,7 @@
   out_hash= out_hash%HASHTBLSIZE;
   position= &(in_hashtbl[out_hash]);
 
-  while(position != NULL){
+  while(1){
     if(*position==NULL)		/* If empty */
       return position;
     
@@ -73,8 +73,6 @@
 
     position= &((*position)->next); /* Try next */
   }
-  return NULL;			/* end of list reached without finding
-                                   an empty position */
 }
 
 /* Generic push function. */
@@ -160,7 +158,9 @@
     else
       def_sym(in_hash, in_string); /* Make symbol */
       
-    new_item->content.ptr= *hash(in_hash, in_string); /* XXX */
+    new_item->content.ptr= *hash(in_hash, in_string); /* The new reference 
+							 shouldn't point at 
+							 NULL */
     new_item->type= ref;
   }
 
@@ -196,26 +196,37 @@
 }
 
 /* Prints the top element of the stack. */
-void print_(stackitem** stack_head)
+extern void print_(stackitem** stack_head)
 {
-  if((*stack_head)==NULL) {
+  stackitem* temp= *stack_head;
+
+  if(temp==NULL) {
     printerr("Stack empty");
     return;
   }
 
-  switch((*stack_head)->type) {
+  while(temp->type==ref) {
+    temp= temp->content.ptr;
+
+    if(temp->type!=ref) {
+      printf("ref-> %s", temp->id);
+      return;
+    }
+  }
+
+  switch(temp->type) {
   case value:
-    printf("%d", (*stack_head)->content.val);
+    printf("%d", temp->content.val);
     break;
   case string:
-    printf("\"%s\"", (char*)(*stack_head)->content.ptr);
-    break;
-  case ref:
-    printf("%s", ((stackitem*)(*stack_head)->content.ptr)->id);
+    printf("\"%s\"", (char*)temp->content.ptr);
     break;
   case symbol:
+  case func:
+    printf("%s", temp->id);
+    break;
   default:
-    printf("%p", (*stack_head)->content.ptr);
+    printf("%p", temp->content.ptr);
     break;
   }
 }
@@ -249,24 +260,60 @@
   }
 }
 
+/* Swap the two top elements on the stack. */
+extern void swap(stackitem** stack_head)
+{
+  stackitem* temp= (*stack_head);
+  
+  if((*stack_head)==NULL) {
+    printerr("Stack empty");
+    return;
+  }
+
+  if((*stack_head)->next==NULL)
+    return;
+
+  *stack_head= (*stack_head)->next;
+  temp->next= (*stack_head)->next;
+  (*stack_head)->next= temp;
+} 
+
+stackitem* copy(stackitem* in_item)
+{
+  stackitem* out_item= malloc(sizeof(stackitem));
+
+  memcpy(out_item, in_item, sizeof(stackitem));
+  out_item->next= NULL;
+
+  return out_item;
+}
+
+
 /* If the top element is a reference, determine if it's a reference to a
    function, and if it is, toss the reference and execute the function. */
 extern void eval(stackitem** stack_head)
 {
   funcp in_func;
+  stackitem* temp= *stack_head;
 
-  if((*stack_head)==NULL || (*stack_head)->type!=ref) {
-    printerr("Stack empty or not a reference");
+  if(temp==NULL) {
+    printerr("Stack empty");
     return;
   }
 
-  if(((stackitem*)(*stack_head)->content.ptr)->type==func) {
-    in_func= (funcp)((stackitem*)(*stack_head)->content.ptr)->content.ptr;
+  while(temp->type==ref)
+    temp= temp->content.ptr;
+
+  if(temp->type==func) {
+    in_func= (funcp)(temp->content.ptr);
     toss(stack_head); 
     (*in_func)(stack_head);
     return;
-  } else
-    printerr("Not a function");
+  }
+
+  push(stack_head, copy(temp));
+  swap(stack_head);
+  toss(stack_head);
 }
 
 /* Make a list. */
@@ -275,27 +322,27 @@
   void* delimiter;
   stackitem *iterator, *temp, *pack;
 
-  if((*stack_head)==NULL) {
-    printerr("Stack empty");
-    return;
-  }
-
   delimiter= (*stack_head)->content.ptr; /* Get delimiter */
   toss(stack_head);
 
   iterator= *stack_head;
 
-  /* Search for first delimiter */
-  while(iterator->next!=NULL && iterator->next->content.ptr!=delimiter)
-    iterator= iterator->next;
-
-  /* Extract list */
-  temp= *stack_head;
-  *stack_head= iterator->next;
-  iterator->next= NULL;
-  
-  if(*stack_head!=NULL && (*stack_head)->content.ptr==delimiter)
+  if(iterator==NULL || iterator->content.ptr==delimiter) {
+    temp= NULL;
     toss(stack_head);
+  } else {
+    /* Search for first delimiter */
+    while(iterator->next!=NULL && iterator->next->content.ptr!=delimiter)
+      iterator= iterator->next;
+    
+    /* Extract list */
+    temp= *stack_head;
+    *stack_head= iterator->next;
+    iterator->next= NULL;
+    
+    if(*stack_head!=NULL && (*stack_head)->content.ptr==delimiter)
+      toss(stack_head);
+  }
 
   /* Push list */
   pack= malloc(sizeof(stackitem));
@@ -396,6 +443,9 @@
   new_head= temp= (*stack_head)->content.ptr;
   toss(stack_head);
 
+  if(temp==NULL)
+    return;
+
   /* Search the end of the list */
   while(temp->next!=NULL)
     temp= temp->next;
@@ -405,24 +455,6 @@
   *stack_head= new_head;	/* ...and voila! */
 }
 
-/* Swap the two top elements on the stack. */
-extern void swap(stackitem** stack_head)
-{
-  stackitem* temp= (*stack_head);
-  
-  if((*stack_head)==NULL) {
-    printerr("Stack empty");
-    return;
-  }
-
-  if((*stack_head)->next==NULL)
-    return;
-
-  *stack_head= (*stack_head)->next;
-  temp->next= (*stack_head)->next;
-  (*stack_head)->next= temp;
-} 
-
 /* Compares two elements by reference. */
 extern void eq(stackitem** stack_head)
 {
@@ -492,6 +524,13 @@
   exit(EXIT_SUCCESS);
 }
 
+/* Clear stack */
+extern void clear(stackitem** stack_head)
+{
+  while(*stack_head!=NULL)
+    toss(stack_head);
+}
+
 int main()
 {
   stackitem* s= NULL;