Factor out mp_seq_index_obj() function to implement .index() on sequences.

py/obj.h

@@ -402,3 +402,4 @@ bool m_seq_get_fast_slice_indexes(machine_uint_t len, mp_obj_t slice, machine_ui
 #define m_seq_cat(dest, src1, len1, src2, len2, item_t) { memcpy(dest, src1, len1 * sizeof(item_t)); memcpy(dest + len1, src2, len2 * sizeof(item_t)); }
 bool mp_seq_cmp_bytes(int op, const byte *data1, uint len1, const byte *data2, uint len2);
 bool mp_seq_cmp_objs(int op, const mp_obj_t *items1, uint len1, const mp_obj_t *items2, uint len2);
+mp_obj_t mp_seq_index_obj(const mp_obj_t *items, uint len, uint n_args, const mp_obj_t *args);

py/objlist.c

@@ -274,24 +274,7 @@ static mp_obj_t list_index(uint n_args, const mp_obj_t *args) {
     assert(2 <= n_args && n_args <= 4);
     assert(MP_OBJ_IS_TYPE(args[0], &list_type));
     mp_obj_list_t *self = args[0];
-    mp_obj_t *value = args[1];
-    uint start = 0;
-    uint stop = self->len;
-
-    if (n_args >= 3) {
-        start = mp_get_index(self->base.type, self->len, args[2]);
-        if (n_args >= 4) {
-            stop = mp_get_index(self->base.type, self->len, args[3]);
-        }
-    }
-
-    for (uint i = start; i < stop; i++) {
-         if (mp_obj_equal(self->items[i], value)) {
-              return mp_obj_new_int(i);
-         }
-    }
-
-    nlr_jump(mp_obj_new_exception_msg(MP_QSTR_ValueError, "object not in list"));
+    return mp_seq_index_obj(self->items, self->len, n_args, args);
 }
 
 static mp_obj_t list_insert(mp_obj_t self_in, mp_obj_t idx, mp_obj_t obj) {

py/sequence.c

@@ -140,3 +140,26 @@ bool mp_seq_cmp_objs(int op, const mp_obj_t *items1, uint len1, const mp_obj_t *
 
     return true;
 }
+
+// Special-case of index() which searches for mp_obj_t
+mp_obj_t mp_seq_index_obj(const mp_obj_t *items, uint len, uint n_args, const mp_obj_t *args) {
+    mp_obj_type_t *type = mp_obj_get_type(args[0]);
+    mp_obj_t *value = args[1];
+    uint start = 0;
+    uint stop = len;
+
+    if (n_args >= 3) {
+        start = mp_get_index(type, len, args[2]);
+        if (n_args >= 4) {
+            stop = mp_get_index(type, len, args[3]);
+        }
+    }
+
+    for (uint i = start; i < stop; i++) {
+         if (mp_obj_equal(items[i], value)) {
+              return mp_obj_new_int_from_uint(i);
+         }
+    }
+
+    nlr_jump(mp_obj_new_exception_msg(MP_QSTR_ValueError, "object not in sequence"));
+}