Java-like enums in GDScript

[hydroper]

I was trying to create an enum whose variants are unique references instantiated from the enum type itself. Variants share similiar methods and virtual properties. E.g., instead of:

enum E { X, Y }

I'd do:

class_name E
const X: E = E.new(15)
const Y: E = E.new(64)

var _v: int

func _init(v: int):
    self._v = v

func value_of() -> int:
    return self._v

There are currently two problems with that:

• GDScript currently doesn't allow a non-constant expression to be assigned to a const
• The const definitions are only visible within the class itself.

So I need to be able to both export the const definitions so they're visible to the public and assign non-constant expressions to these consts. Are there existing proposals for this?

---

static var, finally introduced in Godot 4.1, instead of const works well:

class_name E

static var X: E = E.new("x")

var _s: String

func _init(s: String):
    self._s = s

func to_string() -> String:
    return self._s

You can use it like:

var s = E.X.to_string()

[AThousandShips]

Have you tried static for the visibility part?

[hydroper]

Is there a 4.1 release somewhere? Maybe a GitHub action built for Windows?

[theraot]

The beta is just out at the time of writing: https://godotengine.org/article/dev-snapshot-godot-4-1-beta-1/

[hydroper]

I'm gonna try it; maybe the docs should be updated to say static members are now allowed?

[AThousandShips]

Go ahead and open an issue if one isn't already present here

[hydroper]

@theraot Yeah, using static var works. It's not read-only though, I suppose; but that is really good for me!

[theraot]

If you really need const you can do it.

• The consts are visible outside of the class (if they aren't for you, it is likely due to parsing errors, because of the expression not being constant).

• You need a constant expression, and there is a way, although, you might not like it: Make the class a Resource, create resource files of it, then preload them const blahblah:ClasssName = preload("res://path/to/resource/file.tres") is valid.

---

The way I see it the issue is that calling new with constant values is not a constant expression. Perhaps is it worth changing that for a future release?

[AThousandShips]

• See also Allow adding variant constants to classes #6926