I'm currently working on a simple 'guess the number' game using Lua. I'm programming through an app on my iPad called TouchLua+. One of the game modes is you have a certain amount of time to guess the number. I thought that to do this, I would create a coroutine that counts down from the given time. For some reason, I can't input a number while the coroutine is running. Can anyone help? Here is what I have so far.
target = math.random(1, 100)
coroutine.resume(coroutine.create(function()
for i = 1, roundTime do
sleep(1000)
sys.alert("tock")
end
lose = true
coroutine.yield()
end))
repeat
local n = tonumber(io.read())
if (n > target) then
print("Try a lower number.\n")
elseif (n < target) then
print("Try a higher number.\n")
else
win = true
end
until (lose or win)
return true
Coroutines are not a form of multiprocessing, they are a form of cooperative multithreading. As such, while the coroutine is running, nothing else is running. A coroutine is meant to yield control back to the caller often, and the caller is meant to resume the coroutine so the coroutine can continue where it yielded. You can see how this will appear to be parallel processing.
So in your case you would want to yield from inside the loop, after a small sleep time:
co = coroutine.create(function()
for i = 1, roundTime do
sleep(1)
sys.alert("tock")
coroutine.yield()
end
lose = true
end)
Unfortunately, you can't interrupt io.read(), which means the above is of no use. Ideally you would want a "io.peek" function so you could do the following:
while coroutine.status(co) ~= "dead" do
coroutine.resume(co)
if io.peek() then -- non-blocking, just checks if a key has been pressed
... get the answer and process ...
end
end
I am not aware of a non-blocking keyboard IO in Lua. You could create a C extension that exposes some of C non-blocking keyboard input to Lua, assuming that TouchLua+ supports C extensions. I doubt it, given that it is an iOS app.
It doesn't appear that there is a time loop or callbacks or such, and couldn't find docs. If you have option of creating a text box where user can enter answer and they have to click accept then you can measure how long it took. If there is a time loop you could check time there and show message if run out of time. All this is very easy to do in Corona, maybe not possible in TouchLua+.
Related
I'm building a moving and sensing bot in CoppelliaSim for school. CopelliaSim uses Lua for scripting. Basically every time the bot's forward sensors hit something, one of three if statements will run. I want it to count how many times any of these if statements runs, and once that count gets to a certain amount (like 20), I'll run something else, which will do the same thing (find collisions, add to the count, reach an amount, and switch back to the first).
i=0
result=sim.readProximitySensor(noseSensor) -- Read the proximity sensor
-- If we detected something, we set the backward mode:
if (result>0) then backUntilTime=sim.getSimulationTime()+3
print("Collision Detected")
i=i+1
print(i)
end
result=sim.readProximitySensor(noseSensor0) -- Read the proximity sensor
-- If we detected something, we set the backward mode:
if (result>0) then backUntilTime=sim.getSimulationTime()+3
print("Collision Detected")
i=i+1
print(i)
end
result=sim.readProximitySensor(noseSensor1) -- Read the proximity sensor
-- If we detected something, we set the backward mode:
if (result>0) then backUntilTime=sim.getSimulationTime()+3
print("Collision Detected")
i=i+1
print(i)
end
Above is the start of a function and one of the three If statements. I'm printing just to see if it actually increments. It is printing, but it is not incrementing (just 1 over and over). This bot has 3 sensors on it (an if statement for each sensor) and it adds 1 to i for the first collision and ignores the rest, even if it's from the same sensor. I feel like my problem is just some simple syntax issue with Lua that I don't know and can't find how to properly fix.
I'm happy to provide more code if this little snippet was not sufficient to answer this question.
Assuming that you have a looping function such as sysCall_actuation which is being executed per simulation step. As Joseph Sible-Reinstate Monica has already stated, you are setting your variable i back to zero every time a simulation step is executed. To achieve your goal, you would have to set your variable to 0 outside your function. There are two appropriate approaches to achieve that:
Define the variable outside any function, in the beginning of your file (or before you define any function that uses your variable e.g right before the definition of sysCall_actuation).
-- Beginning of the file.
local i = 0
..
function sysCall_actuation()
..
i = i + 1
..
end
Define your variable in sysCall_init function, which is the appropriate approach in CoppeliaSim.
function sysCall_init()
i = 0
..
end
Finally, you can use your variable in your sysCall_actuation function with basic comparison operations:
function sysCall_actuation()
..
if i > 20 then
i = 0 -- Reset 'i' so this function will not be running every step again and again.
-- Do something here.
..
end
As a side note, practice using local variables whenever you can, to keep the memory clean and avoid having ambiguous variables.
I have this exploit for Murder Mystery 2.
It is a tpcoins and esp exploit. When I enable the tpcoins it will turn off after a few seconds. Is there any way of making it so it stays on?
Here's the code:
function enableTpCoin()
if nameMap ~= "" and wp[nameMap] ~= nil then
if lplr.PlayerGui.MainGUI.Game.CashBag:FindFirstChild("Elite") then
tpCoin(10)
elseif lplr.PlayerGui.MainGUI.Game.CashBag:FindFirstChild("Coins") then
tpCoin(15)
end
end
Trigger to start the script is q.
Short answer, you can't. Since this is script related I'll answer your question.
So each round, the player can only earn 10 coins, and 15 if they have purchased the "Elite" gamepass.
This meaning that the game physically doesn't allow you to add anymore per round. You'll have to execute the code at the launch of every round.
The game has FE, so it's most likely that the original developer of the game has specified the remote events to only accept 10 or 15 coins depending on the boolean value whether the user is "Elite" or not.
Even if Universal Link says the truth, here's the solution.
Create a new function. In that function, do a while loop with a interval (use wait(.1)), and in that while loop, call enableTpCoin().
Now, call spawn() and pass the function you created as an argument.
The code should look like this:
function _loop()
while wait(.1) do
enableTpCoin()
end
end
spawn(_loop)
I was writing a script to move items in and out of storage in a game. I'd planned to allow for item queues in the event that there was not sufficient free space when I ran the script. I'd also planned to allow for more than one queue to exist at a time (ex: a queue to move items into the inventory, and a second queue to move items into the storage).
I originally thought that I should use coroutines to achieve this. The first queue would run until the destination for items (storage or inventory) was full, then would pause using coroutine.yield and allow the next queue to run. The queues would be restarted when a free space opened up.
threads = {}
local co = coroutine.create(function(list, target)
--list: a list of items to be moved
--target: inventory or storage (where the item is to be moved)
while list.n > 0 do
if target.count < target.max then
move(list:last(), target)
else
coroutine.yield()
end
end
end)
threads:append(co)
-- this code would run when free spaces were detected
for i = 1, #threads do
local status = coroutine.resume(threads[i])
if not status then
threads:remove[i]
end
end
However, I realized that I didn't necessarily need to use coroutines.
inventory_lists = {}
-- lists of items to be moved to the inventory
storage_lists = {}
-- lists of items to be moved to the storage
run_threads = function(list, target)
while list.n > 0 and target.count < target.max do
move(list:last(), target)
end
end
-- this code would run when free spaces were detected
for i = 1, #inventory_lists do
run_threads(inventory_lists[i], inventory)
end
for i = 1, #storage_lists do
run_threads(storage_lists[i], storage)
end
These pieces of code accomplish the same thing, and I don't see any reason to use one over the other. Should I avoid using coroutines in this case, since there doesn't seem to be an advantage?
It seems this is an inappropriate use for coroutines as there simply isn't any need to use them: the tables are all available globally, there's no need to store the state of any variables, and all of the information is immediately available (nothing needs to block).
I suppose it's not incorrect in the sense that it still runs, but it's similar to doing
co = coroutine.wrap(function()
print('Hello') coroutine.yield() print('World')
end)
co() co()
When you could simply print 'Hello\nWorld'.
I'm currently working on a game using Roblox (which uses Lua). It is a basically made up of several minigames. At the beginning of each round, all the players in game are put in a table and teleported to an area. That is where the coroutine comes into play. As the round is in progress, I want a coroutine to start. Every second that coroutine checks if the player's health is below zero, and removes them from the currentPlayer table if it is.
Sorry if I am not describing the problem correctly, but the coroutine will not yield. I haven't used coroutines before, so I am probably trying to yield it the wrong way. I know most of you will not be familiar with Roblox, but the Lua syntax is the same.
Can someone please give me an example of how I would end a looping coroutine?
currentPlayers = {}
roundTime = 60
local lookForWinners = coroutine.create(function()
while coroutine.running do
wait(1)
for i, v in pairs(currentPlayers) do
if v.Character.Humanoid.Health <= 0 then
table.remove(currentPlayers, v)
end
end
end
end)
while wait() do
repeat display("Two or more players need to be in the game.", 1) until #_G.plrs > 1 --Ignore, just checks if two+ players are in game.
display("Picking a map...", 3) pickMap()
teleport(0, 500, 0)
coroutine.resume(lookForWinners)
wait(roundTime)
print("Round over")
coroutine.yield(lookForWinners)
end
Lua is a single-threaded language. Coroutines do not cause functions to execute in parallel.
Coroutines are effectively just a way to make a function that can pause its own execution (using coroutine.yield), that can be resumed from outside (using coroutine.resume). There is no "coroutine.running": there's only one line "running" at any given time.
If Roblox were meant for you to use wait() to jump out of the Lua thread, you would write this as a series of loops that check their condition and then call wait():
local currentPlayers={}
local roundTime = 60
while #_G.plrs > 1 do
display("Two or more players need to be in the game.", 1)
wait()
end
display("Picking a map...", 3) pickMap()
teleport(0, 500, 0)
for i=0, roundTime do
for i, v in pairs(currentPlayers) do
if v.Character.Humanoid.Health <= 0 then
table.remove(currentPlayers, v)
end
end
wait(1)
end
print("Round over")
However, this is bad code. (Whenever you write code, let loops with a "wait" function in them serve to indicate that something is being done incorrectly.) You should be using Roblox's Events to handle your game's logic.
Check to see if the game should start only when the number of players changes.
"Look For Winners" only when a Humanoid's health changes (the HealthChanged event).
Run the timer on some kind of timer or interval (don't forget that you'll probably want to end your game early once somebody has won).
Events have many, many advantages over a busy loop; the most visible one will be that your checks occur when the thing they're checking for happens, and not later.
I suggest you follow Stuart's advice to use events; this is mostly to provide additional information on what coroutines are to help you use them correctly.
Think of coroutines as functions that may return values, but with a twist: while a "normal" function completes when it executes return, when you yield from a coroutine, it saves its state, so that resume can then continue from the point where you yielded as if nothing happened. Note that you only yield from a coroutine and only to the point where the resume of that coroutine was done (this is no different from calling a function and returning from it; the control returns to the point where you called the function).
In addition to that, resume and yield calls allow you to pass values to the coroutine and return (intermediate) values from the coroutine. See this SO answer for an example of how this can be used.
One can still return from a coroutine and it's no different from returning from a function, which completes its execution. If you check the status of the coroutine at that time (coroutine.status), it should be "dead".
So, to answer your question how you can end a looping coroutine: you can return from it, you can yield() from it (and never resume it again), or you can call error(), which you can then catch and check for in the result of the resume call. Having said that, I agree with Stuart that it may be the wrong way to solve your problem.
I just started with Lua as part of a school assignment. I'd like to know if there's an easy way to implement profiling for Lua? I need something that displays allocated memory, variables in use regardless of their type, etc.
I've been finding C++ solutions which I have been able to compile successfully but I don't know how to import them to the Lua environment.
I also found Shinny but I couldn't find any documentation about how to make it work.
There are several profilers available that you can check, but most of them target execution time (and are based on debug hook).
To track variables, you will need to use debug.getlocal and debug.getupvalue (from your code or from debug hook).
To track memory usage you can use collectgarbage(count) (probably after collectgarbage(collect)), but this only tells you total memory in use. To track individual data structures, you may need traverse global and local variables and calculate the amount of space they take. You can check this discussion for some pointers and implementation details.
Something like this would be the simplest profiler that tracks function calls/returns (note that you should not trust absolute numbers it generates, only relative ones):
local calls, total, this = {}, {}, {}
debug.sethook(function(event)
local i = debug.getinfo(2, "Sln")
if i.what ~= 'Lua' then return end
local func = i.name or (i.source..':'..i.linedefined)
if event == 'call' then
this[func] = os.clock()
else
local time = os.clock() - this[func]
total[func] = (total[func] or 0) + time
calls[func] = (calls[func] or 0) + 1
end
end, "cr")
-- the code to debug starts here
local function DoSomethingMore(x)
x = x / 2
end
local function DoSomething(x)
x = x + 1
if x % 2 then DoSomethingMore(x) end
end
for outer=1,100 do
for inner=1,1000 do
DoSomething(inner)
end
end
-- the code to debug ends here; reset the hook
debug.sethook()
-- print the results
for f,time in pairs(total) do
print(("Function %s took %.3f seconds after %d calls"):format(f, time, calls[f]))
end