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{{EmphasisBox|'''Note:''' There is no way to run two things at the same time in RBX.lua. That means that you can't use coroutines to run two things at the same time.|green|dark=yes}}

==[http://www.lua.org/pil/9.1.html Coroutine] Manipulation==

The operations related to coroutines comprise a sub-library of the basic library and come inside the table coroutine.

See:

[http://www.lua.org/pil/9.1.html Programming in Lua: Coroutine Basics]<br>
[[Beginners Guide to Coroutines]]

===coroutine.create (f)===


Creates a new coroutine, with body f. f must be a Lua function. Returns this new coroutine, an object with type "thread".

{{Example|
<code lua>
function f (a, b, c)
  print (a, b, c)
end

thread = coroutine.create (f) 
assert (coroutine.resume (thread, 1, 2, 3)) --> 1 2 3
</code>
}}

===coroutine.resume (co [, val1, ···])===


Starts or continues the execution of coroutine co. The first time you resume a coroutine, it starts running its body. The values val1, ··· are passed as the arguments to the body function. If the coroutine has yielded, resume restarts it; the values val1, ··· are passed as the results from the yield.

If the coroutine runs without any errors, resume returns true plus any values passed to yield (if the coroutine yields) or any values returned by the body function (if the coroutine terminates). If there is any error, resume returns false plus the error message.

{{Example|
<code lua>
function f (a, b, c)
  print (a, b, c)
end

thread = coroutine.create (f) 
assert (coroutine.resume (thread, 1, 2, 3)) --> 1 2 3

</code>
}}

'''NOTE:''' The Roblox wait() function internally calls coroutine.yield() so this function will return at that point. The wait() will automatically call coroutine.resume() again when the wait time completes.

===coroutine.running ()===


Returns the running coroutine, or nil when called by the main thread.

{{Example|
<code lua>
co = coroutine.create(function ()
	print("Hi Mom!")
end)
print(coroutine.running ()) --> thread: [hexadecimal memory address]
</code>
}}

===coroutine.status (co)===


Returns the status of coroutine co, as a string: "running", if the coroutine is running (that is, it called status); "suspended", if the coroutine is suspended in a call to yield, or if it has not started running yet; "normal" if the coroutine is active but not running (that is, it has resumed another coroutine); and "dead" if the coroutine has finished its body function, or if it has stopped with an error.

{{Example|
<code lua>
function f (a, b, c)
  print (a, b, c)
end

thread = coroutine.create (f) 
assert (coroutine.resume (thread, 1, 2, 3)) --> 1 2 3
print(coroutine.status (thread)) --> dead

</code>
}}

===coroutine.wrap (f)===


Creates a new coroutine, with body f. f must be a Lua function. Returns a function that resumes the coroutine each time it is called. Any arguments passed to the function behave as the extra arguments to resume. Returns the same values returned by resume, except the first boolean. In case of error, propagates the error.
<code lua>
function perm (a)
	local n = table.getn(a)
	return coroutine.wrap(function () permgen(a, n) end)
end
</code>

{{Example|<code lua>
function f (s)
	print ("Entering f with value", s)
	v = coroutine.yield ()
	print ("After yield, v is", v)
	return 22
end

resumer = coroutine.wrap (f) 
resumer (88) --> Entering f with value 88
resumer (99) --> After yield, v is 99
</code>}}

===coroutine.yield (···)===


Suspends the execution of the calling coroutine. The coroutine cannot be running a C function, a metamethod, or an iterator. Any arguments to yield are passed as extra results to resume. 

{{Example|<code lua>
co = coroutine.create (function ()
	print(coroutine.yield())
end)
coroutine.resume(co)
coroutine.resume(co, 4, 5) --> 4 5
</code>}}