Yielder (nicer way to do custom resuming)

Yielder.lua

local Yielder = {}
Yielder.__index = Yielder

function Yielder.new(): Class
	return setmetatable({
		_thread = nil
	}, Yielder)
end

function Yielder:Yield(...): (...any)
	if self._thread ~= nil then
		error("Cannot yield two threads at once", 2)
	end

	self._thread = coroutine.running()

	return coroutine.yield(...)
end

function Yielder:Resume(...): (...any)
	if self._thread == nil then
		error("No thread to resume", 2)
	end

	local thread = self._thread
	self._thread = nil

	return task.spawn(thread, ...)
end

export type Class = typeof(
	setmetatable({}, Yielder)
)

return Yielder