--- stack/stack.c	2002/01/07 23:09:01	1.1.1.1
+++ stack/stack.c	2002/01/08 14:31:23	1.9
@@ -4,13 +4,14 @@
 #include <stdlib.h>
 /* NULL */
 #include <stddef.h>
+/* dlopen, dlsym, dlerror */
 #include <dlfcn.h>
 
 #define HASHTBLSIZE 65536
 
 typedef struct stack_item
 {
-  enum {value, string, ref, func} type;
+  enum {value, string, ref, func, symbol, list} type;
   union {
     void* ptr;
     int val;
@@ -109,23 +110,36 @@
   mk_hashentry(in_hashtbl, temp, id);
 }
 
+void def_sym(hashtbl in_hashtbl, const char* id)
+{
+  stackitem* temp= malloc(sizeof(stackitem));
+  
+  temp->type= symbol;
+
+  mk_hashentry(in_hashtbl, temp, id);
+}
+
 int push_ref(stackitem** stack_head, hashtbl in_hash, const char* in_string)
 {
-  void* handle;
+  static void* handle= NULL;
   void* symbol;
-  
+
   stackitem* new_item= malloc(sizeof(stackitem));
   new_item->content.ptr= *hash(in_hash, in_string);
   new_item->type= ref;
 
   if(new_item->content.ptr==NULL) {
-    handle= dlopen(NULL, RTLD_LAZY);
+    if(handle==NULL)
+      handle= dlopen(NULL, RTLD_LAZY);    
+
     symbol= dlsym(handle, in_string);
-    if(dlerror()==NULL) {
+    if(dlerror()==NULL) 
       def_func(in_hash, symbol, in_string);
-      new_item->content.ptr= *hash(in_hash, in_string);
-      new_item->type= ref;
-    }
+    else
+      def_sym(in_hash, in_string);
+      
+    new_item->content.ptr= *hash(in_hash, in_string);
+    new_item->type= ref;
   }
 
   push(stack_head, new_item);
@@ -136,10 +150,48 @@
 {
   stackitem* temp= *stack_head;
 
+  if((*stack_head)==NULL)
+    return;
+  
+  if((*stack_head)->type==string)
+    free((*stack_head)->content.ptr);
+
   *stack_head= (*stack_head)->next;
   free(temp);
 }
 
+extern void nl()
+{
+  printf("\n");
+}
+
+void prin(stackitem** stack_head)
+{
+  if((*stack_head)==NULL)
+    return;
+
+  switch((*stack_head)->type) {
+  case value:
+    printf("%d", (*stack_head)->content.val);
+    break;
+  case string:
+    printf("%s", (char*)(*stack_head)->content.ptr);
+    break;
+  case ref:
+    printf("%s", ((stackitem*)(*stack_head)->content.ptr)->id);
+    break;
+  case symbol:
+  default:
+    printf("%p", (*stack_head)->content.ptr);
+    break;
+  }
+}
+
+extern void print(stackitem** stack_head)
+{
+  prin(stack_head);
+  toss(stack_head);
+}
 
 /* print_stack(stack); */
 void print_st(stackitem* stack_head, long counter)
@@ -147,12 +199,9 @@
   if(stack_head->next != NULL)
     print_st(stack_head->next, counter+1);
 
-  if(stack_head->type==value)
-    printf("%ld: %d\n", counter, (int)stack_head->content.val);
-  else if(stack_head->type==string)
-    printf("%ld: \"%s\"\n", counter, (char*)stack_head->content.ptr);
-  else
-    printf("%ld: %p\n", counter, stack_head->content.ptr);
+  printf("%ld: ", counter);
+  prin(&stack_head);
+  nl();
 }
 
 extern void printstack(stackitem** stack_head)
@@ -212,24 +261,56 @@
   return 1;
 }
 
-extern void print(stackitem** stack_head)
+extern void pack(stackitem** stack_head)
 {
+  void* delimiter;
+  stackitem *iterator, *temp, *pack;
+
   if((*stack_head)==NULL)
     return;
 
-  if((*stack_head)->type==value)
-    printf("%d", (*stack_head)->content.val);
-  else if((*stack_head)->type==string)
-    printf("%s", (char*)(*stack_head)->content.ptr);
-  else
-    printf("%p", (*stack_head)->content.ptr);
+  delimiter= (*stack_head)->content.ptr;
+  toss(stack_head);
 
+  iterator= *stack_head;
+
+  while(iterator->next!=NULL && iterator->next->content.ptr!=delimiter)
+    iterator= iterator->next;
+
+  temp= *stack_head;
+  *stack_head= iterator->next;
+  iterator->next= NULL;
+  
+  if(*stack_head!=NULL && (*stack_head)->content.ptr==delimiter)
+    toss(stack_head);
+
+  pack= malloc(sizeof(stackitem));
+  pack->type= list;
+  pack->content.ptr= temp;
+
+  push(stack_head, pack);
+}
+
+extern void expand(stackitem** stack_head)
+{
+  stackitem *temp, *new_head;
+
+  if((*stack_head)==NULL || (*stack_head)->type!=list)
+    return;
+
+  new_head= temp= (*stack_head)->content.ptr;
   toss(stack_head);
+
+  while(temp->next!=NULL)
+    temp= temp->next;
+
+  temp->next= *stack_head;
+  *stack_head= new_head;
 }
 
-extern void nl()
+extern void quit()
 {
-  printf("\n");
+  exit(EXIT_SUCCESS);
 }
 
 int main()
@@ -250,3 +331,7 @@
 
   return EXIT_SUCCESS;
 }
+
+/* Local Variables: */
+/* compile-command:"make CFLAGS=\"-Wall -g -rdynamic -ldl\" stack" */
+/* End: */