Creating Enums

Creating TypedEnum

A new TypedEnum is created using TypedEnum.new. It accepts a constructor function, that is supposed to:

1. create a new enum table (the one that will store items)
2. add items to the enum using the provided add function

Here's an example:

local MyEnum = TypedEnum.new(function(add)
    return {
        MyItem = add("MyItem", 1)
    }
end)

We just created a new enum named MyEnum, with an item named MyItem. Now this enum can be used anywhere:

local myValue = MyEnum.Item
print(myValue.Name) -- "MyItem"

This particular way of creating custom enums allows type inference engine to properly work, and thus gives full autocompletion support!

Type annotations

TypedEnum also provides some public type annotations that you can use.

local MyEnum = TypedEnum.new(function(add)
    return {
        EnumItem1 = add("EnumItem1", 1),
        EnumItem2 = add("EnumItem2", 2),
        EnumItem3 = add("EnumItem3", 3)
    }
end)

export type MyEnum = TypedEnum.TypedEnumItem<number, typeof(MyEnum)>

In the code above, we defined a type MyEnum. It represents all enum items in MyEnum: EnumItem1, EnumItem2 and EnumItem3:

local myValue: MyEnum = MyEnum.EnumItem1 -- ok
local myValue: MyEnum = MyEnum.EnumItem2 -- ok
local myValue: MyEnum = MyEnum.EnumItem3 -- ok

local myValue: MyEnum = 123 -- not ok
local myValue: MyEnum = Enum.AccessoryType.Hat -- not ok
local myValue: MyEnum = MyEnum -- not ok

Enums module

In general, it's a good practice to keep all static data in one place, and it's recommended to have all enums located in a single Enums module, like this:

-- Enums.luau

local Enums = table.freeze({
    Status = TypedEnum.new(function(add)
        return {
            Confusion = add("Confusion", 1),
            Poison = add("Poison", 2)
        }
    end),
})

export type Status = TypedEnum.TypedEnumItem<number, typeof(Enums.Status)>

return Enums

Now, you can use this enum from another script:

-- Example.luau

local Enums = require(path.to.Enums)

local myStatus: Enums.Status = Enums.Status.Confusion
-- wowie!

What's next?

You can check out the API reference to learn more about TypedEnum.

Happy coding!