Exceptions!!!

src/list.h

@@ -10,6 +10,9 @@ DEFOBJTYPE(Cons, CONS, CONSP, {
     LispVal *car;
     LispVal *cdr;
 });
+static ALWAYS_INLINE bool ATOM(LispVal *val) {
+    return !CONSP(val);
+}
 
 static ALWAYS_INLINE bool LISTP(LispVal *obj) {
     return NILP(obj) || CONSP(obj);
@@ -105,6 +108,9 @@ static ALWAYS_INLINE LispVal *LIST_N(int count, ...) {
 
 #define DOTAILS(v, l) for (LispVal *v = (l); !NILP(v); v = XCDR_SAFE(v))
 
+DECLARE_SYMBOL(circular_list_error);
+MAKE_CONDITION_CLASS(circular_list_error);
+
 // return -1 list is circular
 intptr_t list_length(LispVal *list);
 // Return true if the length of LIST == SIZE
@@ -116,6 +122,8 @@ DECLARE_FUNCTION(length_eq, (LispVal * list, LispVal *length));
 DECLARE_FUNCTION(nreverse, (LispVal * list));
 DECLARE_FUNCTION(listp, (LispVal * obj));
 DECLARE_FUNCTION(list, (LispVal * args));
+LispVal *nth(size_t n, LispVal *list);
+DECLARE_FUNCTION(nth, (LispVal * n, LispVal *list));
 static ALWAYS_INLINE void CHECK_LISTP(LispVal *obj) {
     if (!LISTP(obj)) {
         signal_type_error(obj, LIST(Qlist));
@@ -124,6 +132,7 @@ static ALWAYS_INLINE void CHECK_LISTP(LispVal *obj) {
 
 // List utility functions
 DECLARE_FUNCTION(member, (LispVal * elt, LispVal *list, LispVal *pred));
+DECLARE_FUNCTION(member_if, (LispVal * pred, LispVal *list));
 
 DECLARE_FUNCTION(plist_put, (LispVal * plist, LispVal *prop, LispVal *value));
 DECLARE_FUNCTION(plist_get, (LispVal * plist, LispVal *prop, LispVal *def));