Language Transforms

rbx-tsx transforms JavaScript and TypeScript language constructs into idiomatic Luau.

TypeScript	Luau
const / let	local
=== / !==	== / ~=
&& / || / !	and / or / not
a ?? b	if a ~= nil then a else b
a?.b?.c	temp-var optional chaining
cond ? a : b	if cond then a else b
`hello ${name}`	`hello {name}` (Luau string interpolation)
for...of	for _, v in items do
for...in	for k, _ in obj do
Numeric for	for i = 0, n - 1 do
switch/case	if/elseif/else
try/catch/finally	pcall
throw	error()
async/await	Promise-based transform
function* / yield	Coroutine adapter
new Color3() / Color3.new()	Color3.new()
typeof x	typeof(x)
delete obj.key	obj.key = nil
Decorators	Wrapper/descriptor calls
Labeled break	Flag variable pattern
&&= / ||= / ??=	Logical assignment
Destructuring	Local variable extraction
Spread { ...a, ...b }	_merge(a, b)
Classes with extends	Metatables with __index
get x() / set x(v)	Function __index / __newindex dispatch
[key]() {} / "name"() {}	Computed/string method name → Class[key] = function
tag`a${x}b`	tag({ "a", "b" }, x)
LuaTuple<[A, B]> return	(A, B) multiple return values
const [a, b] = tupleCall()	local a, b = tupleCall()

Async, generators, and decorators

Unlike roblox-ts, which relies on installed runtime packages, rbx-tsx inlines the polyfills for these constructs directly into the output:

• async/await compiles to a Promise-based transform.
• function* / yield compiles to a coroutine adapter.
• Class and method decorators compile to wrapper/descriptor calls.

See the async-await, flow, and decorators examples for full input/output pairs.