--- stack/stack.h	2002/03/10 10:06:36	1.9
+++ stack/stack.h	2002/03/10 20:08:47	1.10
@@ -24,6 +24,8 @@
 
 /* First, define some types. */
 
+struct cons_struct;
+
 /* A value of some type */
 typedef struct {
   enum {
@@ -32,7 +34,7 @@
     string,
     func,			/* Function pointer */
     symb, 
-    list
+    tcons
   } type:4;			/* Type of stack element */
 
   union {
@@ -44,6 +46,7 @@
   } gc;
 
   union {
+    struct cons_struct *c;
     void *ptr;			/* Pointer to the content */
     int i;			/* ...or an integer */
     float f;
@@ -51,6 +54,19 @@
 
 } value;
 
+/* An item (value) on a stack */
+typedef struct stackitem_struct
+{
+  value *item;                 /* The value on the stack */
+                               /* (This is never NULL) */
+  struct stackitem_struct *next; /* Next item */
+} stackitem;
+
+typedef struct cons_struct {
+  value *car;
+  value *cdr;
+} cons;
+
 /* A symbol with a name and possible value */
 /* (These do not need reference counters, they are kept unique by
    hashing.) */
@@ -63,21 +79,13 @@
 /* A type for a hash table for symbols */
 typedef symbol *hashtbl[HASHTBLSIZE]; /* Hash table declaration */
 
-/* An item (value) on a stack */
-typedef struct stackitem_struct
-{
-  value *item;			/* The value on the stack */
-				/* (This is never NULL) */
-  struct stackitem_struct *next; /* Next item */
-} stackitem;
-
 /* An environment; gives access to the stack and a hash table of
    defined symbols */
 typedef struct {
   stackitem *gc_ref;
   int gc_limit, gc_count;
 
-  stackitem *head;		/* Head of the stack */
+  cons *head;		/* Head of the stack */
   hashtbl symbols;		/* Hash table of all variable bindings */
   int err;			/* Error flag */
   char *in_string;		/* Input pending to be read */
@@ -108,12 +116,12 @@
 void push_sym(environment*, const char*);
 extern void nl();
 extern void type(environment*);
-void print_h(stackitem*, int);
+void print_h(cons*, int);
 extern void print_(environment*);
 extern void print(environment*);
 extern void princ_(environment*);
 extern void princ(environment*);
-void print_st(stackitem*, long);
+void print_st(cons*, long);
 extern void printstack(environment*);
 extern void swap(environment*);
 extern void rot(environment*);