Godot v4 beta17 - Concatenating typed arrays changes the type

[PabloNeirotti]

Godot version

v4.0.beta17.official [c400205]

System information

Apple M1 Max - macOS Ventura 13.1 (22C65)

Issue description

I am getting an error due to functions no longer returning the correct typed array, when the function concatenates arrays and returns it.

In other words, the following fails:

func add_arrays() -> Array[ClassA]:
	var array_1: Array[ClassA] = []
	var array_2: Array[ClassA] = []
	return array_1 + array_2

I'm assuming when concatenating, the typing changes to a generic Array now? Just a guess.

Steps to reproduce

N/A

Minimal reproduction project

Godot Crash Project.zip

[PabloNeirotti]

Guessing it's related to: #69248

[PabloNeirotti]

I also get errors from using .filter and .map now.

For instance, the following fails:

var array_1: Array[ClassA] = []
var array_2: Array[ClassB] = array_1.map(func(obj: ClassA): return ClassB.new())

I understand this is not what you use a .map for, it's just an example. The point is I shouldn't get a Syntax error from this. One would assume that .map would return a typing different than that of the original Array and that's fine.

I guess a way to type the result could be:

var array_1: Array[ClassA] = []
var array_2: Array[ClassB] = array_1.map(func(obj: ClassA) -> ClassB: return ClassB.new())

[dalexeev]

I also get errors from using .filter and .map now.

See #72566.

[PabloNeirotti]

I also get errors from using .filter and .map now.

See #72566.

Ah excellent, thank you for sharing.