Using '.attr' and '.locals_dict' to create an object with attributes and methods

[birdistheword96]

I'm not sure if I'm missing something obvious here, but I seem to have run into an issue where I can create an object that has attributes, or methods, but not both. I am defining it like this:

// typedef struct _mp_obj_abc_t {...} mp_type_abc 

// STATIC mp_obj_t abc_make_new(...)

// STATIC mp_obj_t abc_add_option()
// STATIC mp_obj_t abc_remove_option()

STATIC void abc_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
    if (dest[0] != MP_OBJ_NULL) {
        return;
    }
    mp_obj_upy_channel_t *self = MP_OBJ_TO_PTR(self_in);
    if (attr == MP_QSTR_text) {
        dest[0] = self->text;
    }
    else if (attr == MP_QSTR_options) {
        dest[0] = self->options;
    }
    else if (attr == MP_QSTR_config) {
        dest[0] = self->config;
    }
}

#define MAP_ENTRY_ABC(n) {MP_OBJ_NEW_QSTR(MP_QSTR_##n), (mp_obj_t)&abc_##n##_obj}

STATIC const mp_map_elem_t abc_locals_dict_table[] = {
    {MP_OBJ_NEW_QSTR(MP_QSTR_add_option), (mp_obj_t)&abc_add_option_obj},
    {MP_OBJ_NEW_QSTR(MP_QSTR_remove_option), (mp_obj_t)&abc_remove_option_obj},
};
STATIC MP_DEFINE_CONST_DICT(abc_locals_dict, abc_locals_dict_table);

const mp_obj_type_t mp_type_abc = {
    { &mp_type_type },
    .name = MP_QSTR_abc,
    .make_new = abc_make_new,
    .locals_dict = (mp_obj_t)&abc_locals_dict,
    .attr = abc_attr,
};

If I comment out the .attr = abc_attr then I get the methods available, but if I leave it defined, the methods disappear and the attributes are available. I know I could define individual methods to return each attribute, but I like the syntax of just using the '.attr_name', and I'm confused why I can't have both. Do I need to define my local methods in the .attr lookup?

I looked in /py/obj.c but couldn't see any obvious reason why this was happening. Any insight would be helpful, thanks!

[stinos]

IIRC if you have .attr then it must be used for methods and attributes. At least I've always done it like this. The file you to look into is runtime.c (the mp_load_xxx functions), not obj.c.

[jimmo]

This used to be true, but it was recently (end of last year) changed to optionally allow both. (See my comment below).

[jimmo]

This is pretty subtle. In attr you need to signal that you still want the locals dict to be searched. See https://github.com/micropython/micropython/blob/master/py/runtime.c#L1177

[jimmo]

See example here: https://github.com/micropython/micropython/blob/master/py/objarray.c#L251

[birdistheword96]

Ah, that's what I missed, thanks @jimmo . Looks like I need to update my local version of Micropython!