Merge pull request #131 from chipaca/dict_fromkeys

Added dict.fromkeys.

1 files changed, 24 insertions, 0 deletions

diff --git a/py/obj.c b/py/obj.c
index 7905f05486..dfb450fb8d 100644
--- a/py/obj.c
+++ b/py/obj.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdarg.h>
+#include <string.h>
 #include <assert.h>
 
 #include "nlr.h"
@@ -229,3 +230,26 @@ uint mp_get_index(const mp_obj_type_t *type, machine_uint_t len, mp_obj_t index)
         nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "%s indices must be integers, not %s", type->name, mp_obj_get_type_str(index)));
     }
 }
+
+// may return NULL
+mp_obj_t mp_obj_len_maybe(mp_obj_t o_in) {
+    mp_small_int_t len = 0;
+    if (MP_OBJ_IS_TYPE(o_in, &str_type)) {
+        len = strlen(qstr_str(mp_obj_str_get(o_in)));
+    } else if (MP_OBJ_IS_TYPE(o_in, &tuple_type)) {
+        uint seq_len;
+        mp_obj_t *seq_items;
+        mp_obj_tuple_get(o_in, &seq_len, &seq_items);
+        len = seq_len;
+    } else if (MP_OBJ_IS_TYPE(o_in, &list_type)) {
+        uint seq_len;
+        mp_obj_t *seq_items;
+        mp_obj_list_get(o_in, &seq_len, &seq_items);
+        len = seq_len;
+    } else if (MP_OBJ_IS_TYPE(o_in, &dict_type)) {
+        len = mp_obj_dict_len(o_in);
+    } else {
+        return NULL;
+    }
+    return MP_OBJ_NEW_SMALL_INT(len);
+}