Set

Set is a Luau module and Wally package which returns a function that converts a list into a set.

What is a Set?

In computer science, a set is an abstract data type that can store unique values, without any particular order.

Want more information? Read the Docs!

Examples of Sets:

Using Roster Notation, a Mathematical Set can be represented as:

A = {4, 2, 1, 3}

An Empty (Null) Set (or a set that contains no values) can be represented as:

A = {}

A Singleton Set (or a set that only contains one value) can be represented as:

A = {x}

Why use Sets in Luau?

Unlike Python, C#, and several other programming languages, in Luau there is no built-in function nor method to check if an item is in a list. Ergo, in Luau, we can just turn our list into a set instead of writing spaghetti code to check if an item is in a list. In Luau, a simple and efficient way to represent a set is to put the set elements as indices in a table. Then, instead of searching a table for a given element, you can just index the table and test whether the result is nil or not.

Still confused? Check Usage for an example.

Install

Installation is simple; choose your workflow.

Roblox Studio Workflow:

1. Get Set from the Roblox Library

2. Parent Set to ReplicatedStorage

3. Require the "Set" ModuleScript from ReplicatedStorage

   local ReplicatedStorage = game:GetService("ReplicatedStorage")
   local Set = require(ReplicatedStorage.Set)
   

Rojo & Wally Workflow:

1. Add Set as a Wally Dependency

   Set = "cizzles/set@x"

2. Use Rojo to point the Wally Packages to ReplicatedStorage

3. Require the "Set" Package (ModuleScript) from ReplicatedStorage

   local ReplicatedStorage = game:GetService("ReplicatedStorage")
   local Set = require(ReplicatedStorage.Packages.Set)
   

Usage

Set can be used in both client (local) scripts and server (regular) scripts. Personally, I recommend the following syntax when using Set:

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local Set = require(ReplicatedStorage.Set)

local Fruits = Set {"Apple", "Banana", "Cherry"}

if Fruits["Cherry"] then
	print("Yes")
else
	print("No")
end

However, you can obviously also use parentheses, semicolons, etc. when declaring Set:

local Fruits = Set({"Apple", "Banana", "Cherry"});

Moreover, Set supports other data types, not just strings:

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local Set = require(ReplicatedStorage.Set)

local Fruits = {"Apple", "Banana", "Cherry"}
local New = Set {true, Fruits, "Cherry"}

if New[Fruits] then
	print("Yes")
else
	print("No")
end

Config

In the "Set" Module you can configure the syntax for Set to be "DEFAULT" or "NEW".

Default Syntax:

ModuleScript:

local Syntax = "DEFAULT"

Usage:

See Above

New Syntax:

ModuleScript:

local Syntax = "NEW"

Usage:

local ReplicatedStorage = game:GetService("ReplicatedStorage")
local Set = require(ReplicatedStorage.Set)

local Fruits = Set.new({"Apple", "Banana", "Cherry"})

if Fruits["Cherry"] then
	print("Yes")
else
	print("No")
end

Changelog

1.0.0

• Initial Release