Tua

Tua (working title) is a superset of Lua 5.3 which aims to provide optional type-checking support to the language. Tua is backwards compatible with standard Lua, has no runtime dependencies, and compiles to plain old Lua.

Compatibility

Tua follows the same basic syntax of Lua, while introducing several optional concepts that allow for static type checking. That means that your existing Lua code is valid Tua code with little to no modification. The Tua compiler produces standard Lua code that can be executed using any supported Lua interpreter or compiler, without requiring any additional runtime dependencies.

Example Syntax

NOTICE: This syntax is a work in progress and may not be representative of final Tua syntax.

local a: int = 123

function b(x: int, y: int) -> float
	return x / y
end	

function c(x: (int, int) -> float) -> float
	return x(5, 6)
end

function d() -> (int, str)
	return 123, "123"
end

local e: { int } = { 1, 2, 3 }
local f: { a: str } = { a = "hello" }

typedef MyType {
	x: int,
	y: str,
	z: float,
	w: str?
}

local g: MyType = {
	x = 456,
	y = "789",
	z = 1.5,
	w = nil
}

global h str
h = "goodbye"

typedef GenericType<T> {
    x: T,
    y: int?
}

local i: GenericType<str> = {
    x = "so generic"
}

function j<T>(x: T) -> str 
    return tostring(x)
end

print(j<int>(123))