Creating a map in C++ as a parameter of a Berry function

[Sebight]

Hello, I am trying to pack data in my C++ code into a Berry map and then call a function that has this map as a parameter.

be_newmap(vm);

[...]

be_pushstring(vm, 'key');

[...]

be_pushint(vm, 22);

[...]

be_data_insert(vm, -3);
be_pop(vm, 2); // Pop key and value

[...]

// Ultimately
be_pcall(vm, 1);

This is the code that I repeat for more key-value pairs, calling the final function only once.

However, after calling this in Berry:

def update(data)
    if (!initialized) 
        return
    end
    print(data['key'])
end

I get this error:
Failed to call update: value 'map' does not support subscriptable

Any idea what's up? Thanks

[s-hadinger]

There is a difference between the internal map structure, and the map instance which wraps the internal structure into a class instance of map.

What I typically do is be_newobject(vm, "map"); to instanciate an empty map and then add elements with berry high level functions.

See https://github.com/arendst/Tasmota/blob/89b4376e3160b304924802de76cd057827f15a64/tasmota/tasmota_xdrv_driver/xdrv_52_3_berry_tasmota.ino#L172

[s-hadinger]

The internal map structure is inside a variable named .p

[Sebight]

Thanks a lot, it works! And also thank you for all the help in the past days! 🙏