Deprecate EnumList

[Sleitnick]

EnumList existed before Luau types. Now that we can create singleton types, we can construct a union of strings to represent an enum.

--!strict

-- Create enum using a union of strings:
type MyEnum = "A" | "B" | "C"

-- Roblox will type-check this to be either A, B, or C, and nothing else:
local myEnum: MyEnum = "A"

The benefits of this:

• Proper intellisense/linting
• Serialization (e.g. Can send across network; can save in DataStore)
• Easier to debug
• No hidden behavior (they're just strings)

[nicholasforeman]

What is your opinion on using a simplified dictionary as an enum, such as

local MyEnum = {
    A = 1,
    B = 2,
    C = 3
}

local myEnum = MyEnum.A

though for this, I'm not sure how the typing would work

[Sleitnick]

@nicholasforeman You could certainly do something like that, but AFAIK there's no way in Luau to indicate that a type should be a key of a given struct. E.g. you can't create a type that represents either A, B, C in MyEnum. Without being able to narrow the type, it becomes a bit difficult. e.g. if you want to create a function that takes a field of MyEnum, there's no way to represent that currently.

This is easy to do in TypeScript, but not possible (yet) in Luau.