7 replies to this topic

[grabie2]

I went into strange problem, when I queued event with strings and tables, in os.pullEventRaw it returned strings and ALL tables were nil. Could someone explain to me why it doesn't work, maybe there is a solution(I don't want to do textutils.serialize, sometimes tables contain functions WITH upvalues)

thanks for replies!

[ChunLing]

Code.

[Eric]

When you use queueEvent, you pass the arguments through to the java code, then they bubble back through. Unfortunately, it is impossible to send tables in this way.

There are a number of ways to solve this. One way would be to wrap queueEvent and pullEvent in lua code that maintains an internal queue, and works with the couroutine API. I think this is possible - have a look at the source code for the parallel API to get ideas.

The easier solution is to just store metadata elsewhere, and use the standard event system to pass a key to that metadata.

eventExtraData = {}
id = 1
function queueMyEvent(...)
	eventExtraData[id] = {...}
	os.queueEvent("my event", id)
	id = id + 1
end



function pullMyEvent()
	local event = {os.pullEvent("my event")}
	local id = event[2]
	local data = eventExtraData[id]
	eventExtraData[id] = nil
	return "my event", unpack(data)
end

[grabie2]

Thanks Eric, I thought that this is the case, but I used Lua only with C api, and that wasn't problem.
But instead of FILO queue that you shown I'll use FIFO, that'll be better for event queue

Again thanks for quick response and help!
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[Eric]

grabie2, on 23 January 2013 - 09:52 AM, said:

But instead of FILO queue that you shown I'll use FIFO, that'll be better for event queue

Are you sure you thought that through? This may not apply to your case, but think about these events:

char f
char a
char i
char l

And a piece of code that gets them one by one and prints. With a FILO (a queue, hence queueEvent()), this will print "fail", but with a FIFO (a stack), you get "liaf".

[KaoS]

Eric, on 23 January 2013 - 09:58 AM, said:

grabie2, on 23 January 2013 - 09:52 AM, said:

But instead of FILO queue that you shown I'll use FIFO, that'll be better for event queue

Are you sure you thought that through? This may not apply to your case, but think about these events:

char f
char a
char i
char l

And a piece of code that gets them one by one and prints. With a FILO (a queue, hence queueEvent()), this will print "fail", but with a FIFO (a stack), you get "liaf".

I disagree.... you press f-a-i-l and it queues "f" first, then "a", then "i", then "l", FIFO means "f" comes out first 'cos it went in first so you keep the order of events.

[Eric]

Derp. I was confused by grabie calling my code a FILO when it is in fact a fifo.

[grabie2]

Oww right, derp.
I looked at your code and somehow seen FILO queue, derp.
Sorry for that.
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