roblox-ts

Data Type Math

This page explains how to represent operator overloading in TypeScript for Roblox data types.

One of the few downsides to using TypeScript is that it does not support operator overloading.

Usually this is fine, but with Roblox there are a few built-in classes that require operator overloading to use:

  • CFrame (used for Instance Translations)
  • UDim
  • UDim2 (Used for Roblox GUI Translation & Sizing)
  • Vector2
  • Vector2int16
  • Vector3 (Used for Instance Positioning & Velocities)
  • Vector3int16

To get around this, roblox-ts introduces a few macro methods on each of these classes in the form of “add”, “sub”, “mul”, and “div”.

let v0 = new Vector3(1, 2);
let v1 = new Vector3(3, 4);
let v2 = v0.add(v1);

the following will compile into:

local v0 = Vector3.new(1, 2);
local v1 = Vector3.new(3, 4);
local v2 = (v0 + v1);

The macro calls are properly typed so that TypeScript understands statically what each call returns.

let cf = new CFrame();
let v3 = new Vector3();
let x = cf.mul(v3); // TypeScript knows that `x` is of type `Vector3`

Additionally, you can chain these calls together and additional parentheses will ensure that the intended order is followed:

let x = v0
    .add(v1)
    .mul(v2)
    .div(v3)
    .sub(v4);

which compiles into

local x = ((((v0 + v1) * v2) / v3) - v4);