simplified the kbtree iter a bit

diff --git a/kbtree.h b/kbtree.h
index 4eff10ece9d8c29ada3b2c6f05e7edfbb8ec4c47..79ab121acd62ccb6b7f50fa7d667b4440f54424a 100644 (file)
--- a/kbtree.h
+++ b/kbtree.h
@@ -317,11 +317,11 @@ typedef struct {
                return kb_delp_##name(b, &k);                                                                   \
        }
 
-#define kb_itr_key(type, itr) __KB_KEY(type, (itr)->p->x)[(itr)->p->i]
-
 #define __KB_ITR(name, key_t) \
        static inline void kb_itr_first_##name(kbtree_##name##_t *b, kbitr_t *itr) \
        { \
+               itr->p = 0; \
+               if (b->n_keys == 0) return; \
                itr->p = itr->stack; \
                itr->p->x = b->root; itr->p->i = 0; \
                while (itr->p->x->is_internal && __KB_PTR(b, itr->p->x)[0] != 0) { \
@@ -388,6 +388,8 @@ typedef struct {
 #define kb_itr_first(name, b, i) kb_itr_first_##name(b, i)
 #define kb_itr_get(name, b, k, i) kb_itr_get_##name(b, k, i)
 #define kb_itr_next(name, b, i) kb_itr_next_##name(b, i)
+#define kb_itr_key(type, itr) __KB_KEY(type, (itr)->p->x)[(itr)->p->i]
+#define kb_itr_valid(itr) ((itr)->p >= (itr)->stack)
 
 #define kb_size(b) ((b)->n_keys)