how to give an os.pullEvent a timeout? (And return nil?)

local myTimer = os.startTimer(5)
while true do
  local a, b, c, d, e = os.pullEvent()
  if a == "timer" and b == myTimer then --# act when myTimer triggers
    --# do timer stuff
  elseif a == "myEvent" then --# act when the event you are waiting for triggers
    --# do event stuff
  end
end

Dog, on 21 November 2016 - 03:12 AM said:

I believe it's just rednet.receive(number), and yeah, os.pullEvent doesn't have a timeout. You're probably best using a timer, then act on the event captured with an if/elseif statement.

local myTimer = os.startTimer(5)
while true do
  local a, b, c, d, e = os.pullEvent()
  if a == "timer" and b == myTimer then --# act when myTimer triggers
	--# do timer stuff
  elseif a == "myEvent" then --# act when the event you are waiting for triggers
	--# do event stuff
  end
end

local iEventTime = 0
local tEventData
os.pullEventRaw = function (event, timeout)
   iEventTime = os.time()
   while true do
	  tEventData = {coroutine.yield()}
	  if not event or tEventData[1] == event then
		 return unpack (tEventData)
	  elseif timeout and os.time()-iEventTime >= timeout then
		 return nil
	  end
   end
end
os.pullEvent = function (event, timeout)
   os.pullEventRaw (event, timeout)
   if tEventData[1]=="terminate" then
	  error ("terminated", 0)
   else
	  return unpack (tEventData)
   end
end

Bomb Bloke, on 22 November 2016 - 03:43 PM said:

And if event == nil…? :P/>

Frankly though, having os.pullEventRaw() return nil is very limiting. Performing the timer check within one's own code allows for much more flexible solutions.

local received = false;
function waitBeforeFunction()
sleep(5);
if received == false then
  myfunction();
end
return;
end
function rednetReceive()
local event, message, id = os.pullEvent("rednet_receive");
received = true;
--# Do someting with event, message and id.
return;
end
parallel.waitForAny(rednetReceive, waitBeforeFunction);