await wrapper using coroutines (related to this gist: https://gist.github.com/creationix/5291866)

await.lua

function await(continuation)
	local coro = coroutine.running()
	local result
	local async
	continuation(function(err, value)
		if async == nil then
			async = false
			result = value
			if err then error(err) end
			return
		end
		if err then
			-- todo, marshall the error into the coroutine
			print(err)
		else
			coroutine.resume(coro, value)
		end
	end)
	
	if async == nil then
		async = true
		return coroutine.yield()
	end
	return result
end

function sleep(ms)
	return function(callback)
		setTimeout(callback, ms)
	end
end


coroutine.wrap(function()
	for i=1, 10 do
		console.log(i)
		await(sleep(1000))
	end
end)()

process:loop()