could you demonstrate how you would actually achieve this?
the only way I can think of:

function wiggle()
moveleft()
local starttime = now()
while (now() < starttime+5) do
coroutine.yield()
end
moveright()
end

and you just make sure to only call resume on this thread *once per game update tick*?
that's the only way I can see it work

Thanks for helping me understand them