`is` statement cant read scope

[bend-n]

Godot version

9c960a8

System information

Archlinux x11

Issue description

Steps to reproduce

var c := 4
var b := 2
var a := c is b

Minimal reproduction project

na

[dalexeev]

is is not a comparison operator, it is a type checking operator.

[bend-n]

i know that

it should return true

[akien-mga]

This is an expected compat breaking change from #73489.

What's your use case for c is b? It doesn't make sense. It used to work, but it's not what the is operator is for.

@vonagam I feel the error message could maybe be improved though, it could say that it expects a type name instead of saying it doesn't see b.

[dalexeev]

The right operand of the is operator must be a type. 2 is not a type. If you want to compare values or references, there is the == operator, is_same(), is_equal_approx(), etc.

[bend-n]

I use it to check if a InputEvent is a InputEventMouseMotion or other event see here

This example didnt work ever, so sorry if that was confusing, but the error should have been Invalid "is" test: the right operand isn't a type (neither a native type nor a script). instead, i think?

Heres a better example:

	var t = InputEvent
	print(4 is t)

[dalexeev]

See #73489:

Since right side now needs to be compile time known type to support previously available functionality, where a type was intended to be variable, add is_instance_of utility function to GDScript.

is_instance_of(a, TYPE_INT)
is_instance_of(a, RefCounted)
is_instance_of(a, A)

[bend-n]

@dalexeev I see, thanks for explaining.

[vonagam]

I feel the error message could maybe be improved though, it could say that it expects a type name instead of saying it doesn't see b.

Message comes from inside resolve_datatype call. Unfortunately, I do not see an easy (or medium easy) way to detect if TypeNode points at some existing non-constant variable.