How to get an instance of the current main scene in a static function of another class

Question

The situation is as follows:
1) There is a script attached to the main scene.
2) There is a separate class script, which has a static function.
3) There is a signal in the main script, which calls a function in the same script.
I need to call this signal (emit_signal) from this static function and for this I need an instance of the current main.
How do I get it without a global variable?

Answer 1

When the script is ready, connect your signal to the outside script. That function name will be your 3rd argument. So assuming "mycustomsignal" is the signal you made (1st argument), target is your separate class object (you'll have to attach it to a node, maybe a plain Node2d) and then the 3rd is whatever function you want to call.

func _ready():
    self.connect("my_custom_signal", target, "_separate_class_function")