Array:sort_custom Usage

[bojjenclon]

I've been trying to sort an array using the sort_custom method, but I can't figure out the proper way to use it. It expects a Godot object and a method to call within it. But everything in Lua is a table. What am I supposed to pass in?

[gilzoide]

Well, not everything in Lua is a table. Since we're using the FFI, some things are actual Godot Objects, including the script instance owner.

I just realized that I forgot to make script instances, e.g. self in script methods, be considered Objects when creating Variants. So, for now, you'd have to pass self.__owner, which is very annoying:

some_array:sort_custom(self.__owner, 'some_method_name')`

At least this is easy to fix =]

Now, if you have another object with the right method, you can use it right away:

local sorter_object = GD.load('res://mysortingobject.gd_or_lua_or_cs_or...'):new()
some_array:sort_custom(sorter_object, 'some_method_name')

Another thing I was thinking that could be done is a way to wrap functions and regular tables as Godot Objects, just like there is one for coroutines. This should make this kind of method passing easier. It could even be done transparently, creating a Variant from a Lua function would create this object automatically.

If it's done, we could patch those functions that accept methods to check for function values, so that we could do like some_array:sort_custom(function(...) end) without needing to pass a method name.

[bojjenclon]

I see, the self.__owner explains the issue I was having then. I had tried to use a method bound to self and it wasn't working.

I like the idea of having a way to wrap Lua functions or table as objects. I wouldn't say its "high priority" or anything since I can get it to work without that feature, but being able to dynamically create these things could be very helpful. Essentially would let us use anonymous functions/lambda type functionality for any Godot method that normally requires an object passed in.

[gilzoide]

Ok, so it turns out script instances were being considered as object correctly when creating Variants, but Array.sort_custom was expecting an actual godot_object * and its implementation is not based on Variants, so a new conversion needed to be done.

e82551fc1f40e7bd86825a15765b08c787ede03c fixes this, so at least some_array:sort_custom(self, 'some_method_name') is now possible.

Someday we might make it accept actual Lua functions, but for now this fix is enough for being equivalent to GDScript.

[bojjenclon]

Oh nice, yeah I think this is very good for the time being. Thanks for the fix!