py/dynruntime.h: Add mp_obj_get_array() function.

Signed-off-by: Damien George <damien@micropython.org>

py/dynruntime.h

@@ -81,6 +81,7 @@ static inline void *m_realloc_dyn(void *ptr, size_t new_num_bytes) {
 
 #define mp_type_type                        (*mp_fun_table.type_type)
 #define mp_type_str                         (*mp_fun_table.type_str)
+#define mp_type_tuple                       (*((mp_obj_base_t *)mp_const_empty_tuple)->type)
 #define mp_type_list                        (*mp_fun_table.type_list)
 #define mp_type_EOFError                    (*(mp_obj_type_t *)(mp_load_global(MP_QSTR_EOFError)))
 #define mp_type_IndexError                  (*(mp_obj_type_t *)(mp_load_global(MP_QSTR_IndexError)))
@@ -121,6 +122,7 @@ static inline void *m_realloc_dyn(void *ptr, size_t new_num_bytes) {
 
 #define mp_obj_len(o)                       (mp_obj_len_dyn(o))
 #define mp_obj_subscr(base, index, val)     (mp_fun_table.obj_subscr((base), (index), (val)))
+#define mp_obj_get_array(o, len, items)     (mp_obj_get_array_dyn((o), (len), (items)))
 #define mp_obj_list_append(list, item)      (mp_fun_table.list_append((list), (item)))
 
 static inline mp_obj_t mp_obj_new_str_of_type_dyn(const mp_obj_type_t *type, const byte *data, size_t len) {
@@ -251,4 +253,23 @@ static inline void mp_raise_OSError_dyn(int er) {
 #define mp_obj_get_float(o)         (mp_obj_get_float_to_d((o)))
 #endif
 
+/******************************************************************************/
+// Inline function definitions.
+
+// *items may point inside a GC block
+static inline void mp_obj_get_array_dyn(mp_obj_t o, size_t *len, mp_obj_t **items) {
+    const mp_obj_type_t *type = mp_obj_get_type(o);
+    if (type == &mp_type_tuple) {
+        mp_obj_tuple_t *t = MP_OBJ_TO_PTR(o);
+        *len = t->len;
+        *items = &t->items[0];
+    } else if (type == &mp_type_list) {
+        mp_obj_list_t *l = MP_OBJ_TO_PTR(o);
+        *len = l->len;
+        *items = l->items;
+    } else {
+        mp_raise_TypeError("expected tuple/list");
+    }
+}
+
 #endif // MICROPY_INCLUDED_PY_DYNRUNTIME_H