Custom Enum class for Roblox

CustomEnum.luau

--[[
EXAMPLE USAGE:
local BaseState = CustomEnum.Class.new("BaseState", {
    "Dead",
    "Alive",
        "Walking",
})

local SubState = CustomEnum.Class.New("CombatStates", {
    "Attacking",
    "Dodging",
    "Blocking",
})

BaseState:AddItem(SubState)

SubState.Attacking:IsA(BaseState) -- true
BaseState.Dead:IsA(SubState) -- false

print(BaseState.SubState.Attacking) -- "Attacking"
]]

local EnumConstructor = {
	Class = {},
	Item = {},
}
local EnumItem = {}
local EnumClass = {}

function EnumItem.__index(self, key)
	local FoundValue = rawget(EnumItem, key)
	if not FoundValue then
		error(`{key} is not a valid member of "{self._MainParent.Name}.{self.Name}"`)
	end

	return FoundValue
end

function EnumClass.__index(self, key)
	local FoundValue = rawget(self._Items, key) or rawget(EnumClass, key)
	if not FoundValue then
		error(`{key} is not a valid member of "{self.Name}"`)
	end

	return FoundValue
end
function EnumClass.__tostring(self)
	local HasParent = rawget(self, "_MainParent") ~= nil
	local Prefix = HasParent and `{self._MainParent.Name}.` or ``
	return `{Prefix}{self.Name}`
end

function EnumItem:IsA(Class)
	if typeof(Class) == "table" and Class.Type == "EnumClass" then
		Class = Class.Name
	end

	assert(typeof(Class) == "string", `invalid argument #2 to 'IsA' (string expected, got {typeof(Class)})`)
	for ParentName, ParentClass in self._Parents do
		if ParentName == Class or ParentClass:IsA(Class) then
			return true
		end
	end
	return self._Parents[Class] ~= nil
end
function EnumItem:GetFullName()
	local FullName = self.Name
	local Parent = rawget(self, "_MainParent")
	while Parent do
		FullName = `{Parent.Name}.{FullName}`
		Parent = rawget(Parent, "_MainParent")
	end

	return FullName
end
EnumItem.__tostring = EnumItem.GetFullName

function EnumClass:GetEnumItems()
	return self._Items
end
function EnumClass:IsA(Class)
	if typeof(Class) == "table" and Class.Type == "EnumClass" then
		Class = Class.Name
	end

	assert(typeof(Class) == "string", `invalid argument #2 to 'IsA' (string expected, got {typeof(Class)})`)
	for ParentName, ParentClass in self._Parents do
		if ParentName == Class or ParentClass:IsA(Class) then
			return true
		end
	end

	return self._Parents[Class] ~= nil
end
function EnumClass:AddItem(EnumObject)
	assert(
		type(EnumObject) == "table",
		`invalid argument #1 to 'AddItem' (EnumItem or EnumClass expected, got {typeof(EnumObject)})`
	)
	assert(
		EnumObject.Type == "EnumItem" or EnumObject.Type == "EnumClass",
		`invalid argument #1 to 'AddItem' (EnumItem or EnumClass expected, got {typeof(EnumObject)})`
	)

	self._Items[EnumObject.Name] = EnumObject
	EnumObject._Parents[self.Name] = self
	if rawget(EnumObject, "_MainParent") == nil then
		EnumObject._MainParent = self
	end
end
function EnumClass:GetFullName()
	local FullName = self.Name
	local Parent = rawget(self, "_MainParent")
	while Parent do
		FullName = `{Parent.Name}.{FullName}`
		Parent = rawget(Parent, "_MainParent")
	end

	return FullName
end
EnumClass.__tostring = EnumClass.GetFullName

function EnumConstructor.Item.new(ParentClass, ItemName)
	assert(
		type(ParentClass) == "table" and ParentClass.Type == "EnumClass",
		`invalid argument #1 to 'EnumItem.new' (EnumClass expected, got {typeof(ParentClass)})`
	)
	assert(
		type(ItemName) == "string",
		`invalid argument #2 to EnumItem.new (string expected, got {typeof(ItemName)})`
	)

	local Item = setmetatable({
		Name = ItemName,
		Type = "EnumItem",
		_Parents = {},
		_MainParent = ParentClass,
	}, EnumItem)

	ParentClass:AddItem(Item)
	return Item
end
function EnumConstructor.Class.new(ClassName, Items)
	local ItemsHolder = {}
	local Class = setmetatable({
		Name = ClassName,
		Type = "EnumClass",
		_Items = ItemsHolder,
		_Parents = {},
		_MainParent = nil,
	}, EnumClass)

	if Items ~= nil then
		assert(
			type(Items) == "table",
			`invalid argument #2 to EnumClass.new (table expected, got {type(Items)})`
		)

		for _, Item in Items do
			if typeof(Item) == "string" then
				EnumConstructor.Item.new(Class, Item)
			elseif typeof(Item) == "table" and (Item.Type == "EnumItem" or Item.Type == "EnumClass") then
				Class:AddItem(Item)
			end
		end
	end

	return Class
end

return EnumConstructor

Thats working nice! Thanks :D